Thermal field structure of single crystal furnace
By designing a single crystal furnace thermal field structure composed of upper, middle and lower barrels overlapping, using three-layer insulation layer and carbon-carbon composite insulation barrel, the traditional heat field replacement cycle is short and the cost is high. The problem of low service life achieves more efficient insulation effect and longer service life.
Patent Information
- Application Number
- CN202420741208.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-11
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-04-11
AI Technical Summary
The thermal field of traditional single crystal furnaces is wrapped with graphite felt, resulting in a short replacement cycle, high cost and low service life, and it is impossible to effectively reduce the oxygen content and thermal field power of single crystal silicon.
A single crystal furnace thermal field structure is designed, including an insulation component composed of an upper barrel, a middle barrel and a lower barrel. It is equipped with a crucible and a heater inside, and is electrically connected to the heater using graphite electrodes and is heated through three layers. The layer and carbon-carbon composite insulation barrel improve the insulation effect.
This structure significantly improves the insulation effect through the three-layer insulation layer and the carbon-carbon composite insulation barrel, reduces the oxygen content of single crystal silicon, and reduces the number of replacements of the insulation layer, extends the service life, and reduces the heat of the single crystal furnace. power of the field.
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of solar photovoltaics, in particular to a single crystal furnace thermal field structure. Background Art
[0002] Currently, single crystal silicon rods are primarily produced using the Czochralski method in a single crystal furnace. The furnace houses a quartz crucible and a supporting rim. During the production of single crystal silicon rods, polycrystalline silicon feedstock is placed in the crucible. After heating the polycrystalline silicon feedstock with an external heater to form a melt, a seed crystal is inserted into the melt and pulled through a series of processes, including seeding, shouldering, shoulder rotation, equalizing the diameter, and finishing, to produce a single crystal silicon rod. An insulation assembly is installed around the crucible and heater to reduce heat loss. This insulation assembly and its internal components are generally referred to as the thermal field.
[0003] The installed capacity of single crystal furnaces in China has exploded, and their sizes are increasing. The size of the accompanying heat fields is also changing rapidly. This increase in heat field size inevitably increases the amount of insulation materials used in these fields. Traditional single crystal furnace heat fields are wrapped with graphite felt to insulate and reduce power consumption. However, with traditional wrapping methods, the replacement cycle is 3-4 months, which increases the cost of the heat field and significantly reduces its lifespan. In light of this, we propose a new heat field structure for single crystal furnaces. Utility Model Content
[0004] The purpose of the present invention is to provide a single crystal furnace thermal field structure to solve the problems raised in the above background technology.
[0005] To achieve the above objectives, the present invention provides the following technical solutions:
[0006] A single crystal furnace thermal field structure includes a heat preservation assembly, which is composed of an upper barrel, a middle barrel, and a lower barrel, which are overlapped in sequence from top to bottom. A crucible and a heater are arranged inside the heat preservation assembly. The heater is sleeved on the outside of the crucible. A guide tube is connected above the crucible. A hard felt is provided at the lower end of the heat preservation assembly. A receiving cavity is defined in the hard felt. A graphite electrode is embedded in the receiving cavity. The graphite electrode is electrically connected to the heater.
[0007] The upper barrel, middle barrel, and lower barrel each include an inner insulation barrel, an outer insulation barrel, an upper cover, a lower cover, and an insulation layer completely filled between the inner insulation barrel and the outer insulation barrel. The tops of the inner insulation barrel and the outer insulation barrel are respectively clamped with the two ends of the upper cover, and the bottoms of the inner insulation barrel and the outer insulation barrel are respectively clamped with the two ends of the lower cover.
[0008] The bottom of the upper barrel is clamped with the top of the middle barrel, and the bottom of the middle barrel is clamped with the top of the lower barrel;
[0009] The thermal insulation layer comprises an inner thermal insulation layer, a middle thermal insulation layer and an outer thermal insulation layer which are sequentially arranged from the inside to the outside.
[0010] Preferably, the inner insulation layer, the middle insulation layer and the outer insulation layer are fixed to the inner insulation barrel by tying with hoops; the outer insulation barrel is fixed to the upper cover plate and the lower cover plate by carbon-carbon nails respectively.
[0011] Preferably, a first stop is provided at the upper end of the inner heat-insulating barrel, a second stop is provided at the upper end of the outer heat-insulating barrel, and the upper cover plate is respectively engaged with the first stop of the inner heat-insulating barrel and the second stop of the outer heat-insulating barrel; a first step is provided at the lower end of the inner heat-insulating barrel, a third stop is provided at the lower end of the outer heat-insulating barrel, and the lower cover plate is respectively engaged with the first step of the inner heat-insulating barrel and the third stop of the outer heat-insulating barrel.
[0012] Preferably, a second step is provided on the inner side of the top of the middle barrel, a third step is provided on the outer side of the bottom of the middle barrel, a fourth step is provided on the inner side of the top of the lower barrel, the outer side of the bottom of the upper barrel is engaged with the second step, and the third step of the bottom of the middle barrel is engaged with the fourth step of the top of the lower barrel.
[0013] Preferably, the inner insulation barrel and the outer insulation barrel are made of graphite or carbon-carbon composite material.
[0014] Preferably, the upper cover plate and the lower cover plate are made of carbon-carbon composite material.
[0015] Preferably, the filling thickness ratio of the inner insulation layer, the middle insulation layer and the outer insulation layer is 1:2:1.
[0016] Preferably, the inner insulation layer is made of asphalt-based graphite soft felt or asphalt-based graphite carbonized felt.
[0017] Preferably, the middle insulation layer is made of viscose-based graphite soft felt.
[0018] Preferably, the outer thermal insulation layer is made of aerogel carbon fiber composite soft felt.
[0019] Compared with the prior art, the beneficial effects of the present invention are:
[0020] 1. The thermal field structure of the single crystal furnace consists of an inner insulation barrel, an outer insulation barrel, an insulation layer, and upper and lower cover plates to form a closed thermal field environment. The three-layer insulation layer, heat radiation method, and carbon-carbon composite insulation barrel improve the insulation effect, further reduce the oxygen content of single crystal silicon, and reduce the number of replacement times of the insulation layer. The inner insulation layer has a low thermal conductivity coefficient, so the inner insulation layer only needs to be replaced when it ages, without replacing the inner and outer insulation barrels. This extends the service life of the insulation components and reduces the thermal field power of the single crystal furnace.
[0021] 2. The single crystal furnace heat field has a simple structure and is easy to use. The upper cover is respectively engaged with the first stop of the inner insulation barrel and the second stop of the outer insulation barrel, and the lower cover is respectively engaged with the first step of the inner insulation barrel and the third stop of the outer insulation barrel. This allows the heat field to be accurately installed during installation, so that its temperature is evenly distributed, which also improves the efficiency of heat field installation, reduces rework, and effectively reduces costs.
[0022] 3. The insulation component of the single crystal furnace thermal field structure is composed of an upper barrel, a middle barrel, and a lower barrel, which are overlapped in sequence from top to bottom. The outer side of the bottom of the upper barrel is clamped with the second step of the middle barrel, and the third step of the bottom of the middle barrel is clamped with the fourth step of the top of the lower barrel, which further reduces the heat loss inside the thermal field. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a schematic diagram of the overall structure of the utility model;
[0024] Figure 2 This is a top view of the internal structure of the upper barrel in the insulation assembly of the present invention;
[0025] Figure 3 This is an assembly diagram of the inner insulation barrel, outer insulation barrel and upper cover of the utility model;
[0026] Figure 4 This is an assembly diagram of the inner insulation barrel, outer insulation barrel and lower cover plate of the utility model;
[0027] Figure 5 This is an assembly diagram of the upper barrel and the middle barrel of the utility model;
[0028] Figure 6 This is an assembly diagram of the middle barrel and the lower barrel of the utility model.
[0029] In the figure: 1. Crucible; 2. Heater; 3. Guide tube; 4. Graphite electrode; 51. First stop; 52. Second stop; 53. First step; 54. Third stop; 55. Carbon-carbon nail; 6. Inner insulation barrel; 7. Outer insulation barrel; 8. Inner insulation layer; 9. Middle insulation layer; 10. Outer insulation layer; 11. Upper cover; 12. Lower cover; 100. Upper barrel; 200. Middle barrel; 201. Second step; 202. Third step; 300. Lower barrel; 301. Fourth step. DETAILED DESCRIPTION
[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0032] In the description of this patent, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," and "set" should be understood in a broad sense. For example, they can refer to fixed connection or set, detachable connection or set, or integral connection or set. Those skilled in the art will understand the specific meanings of the above terms in this patent based on the specific circumstances.
[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "several" means two or more, unless otherwise specifically defined.
[0034] See also Figures 1-6 As shown, the utility model provides a technical solution:
[0035] like Figure 1 、 2As shown, a single crystal furnace thermal field structure includes a heat preservation assembly, which is composed of an upper barrel 100, a middle barrel 200, and a lower barrel 300, which are overlapped from top to bottom. A crucible 1 and a heater 2 are provided inside the heat preservation assembly. The heater 2 is sleeved on the outside of the crucible 1. A guide tube 3 is connected above the crucible 1. A hard felt 5 is provided at the lower end of the heat preservation assembly. A receiving cavity is defined in the hard felt 5. A graphite electrode 4 is embedded in the receiving cavity. The graphite electrode 4 is electrically connected to the heater 2, generates heat through electric current, and transfers the heat to the silicon material, causing the silicon material to gradually heat up to the temperature required for melting and crystallization.
[0036] The upper barrel 100, the middle barrel 200, and the lower barrel 300 each include an inner insulation barrel 6, an outer insulation barrel 7, an upper cover plate 11, a lower cover plate 12, and an insulation layer completely filled between the inner insulation barrel 6 and the outer insulation barrel 7. The tops of the inner insulation barrel 6 and the outer insulation barrel 7 are respectively clamped with the two ends of the upper cover plate 11, and the bottoms of the inner insulation barrel 6 and the outer insulation barrel 7 are respectively clamped with the two ends of the lower cover plate 12, thereby forming a closed thermal field environment;
[0037] The bottom of the upper barrel 100 is clamped with the top of the middle barrel 200, and the bottom of the middle barrel 200 is clamped with the top of the lower barrel 300, which can prevent heat leakage inside the insulation component;
[0038] The thermal insulation layer includes an inner thermal insulation layer 8, a middle thermal insulation layer 9 and an outer thermal insulation layer 10 which are sequentially arranged from the inside to the outside.
[0039] As an implementation method of this embodiment, Figure 1 、 2 As shown, the inner insulation layer 8, the middle insulation layer 9 and the outer insulation layer 10 are fixed to the inner insulation barrel 6 by means of a clamp; the outer insulation barrel 7 is fixed to the upper cover plate 11 and the lower cover plate 12 by means of carbon-carbon nails 55 respectively, so as to enhance the stability between the insulation layer and the inner insulation barrel 6 and the outer insulation barrel 7.
[0040] As an implementation method of this embodiment, Figure 3 、 4 As shown, a first stop 51 is provided at the upper end of the inner heat-insulating barrel 6, a second stop 52 is provided at the upper end of the outer heat-insulating barrel 7, and the upper cover plate 11 is respectively engaged with the first stop 51 of the inner heat-insulating barrel 6 and the second stop 52 of the outer heat-insulating barrel 7; a first step 53 is provided at the lower end of the inner heat-insulating barrel 6, a third stop 54 is provided at the lower end of the outer heat-insulating barrel 7, and the lower cover plate 12 is respectively engaged with the first step 53 of the inner heat-insulating barrel 6 and the third stop 54 of the outer heat-insulating barrel 7 to form a closed thermal field environment and reduce heat loss inside the thermal field.
[0041] In this embodiment, if Figure 5 、 6As shown, a second step 201 is provided on the inner side of the top of the middle barrel 200, a third step 202 is provided on the outer side of the bottom of the middle barrel 200, and a fourth step 301 is provided on the inner side of the top of the lower barrel 300. The outer side of the bottom of the upper barrel 100 is snap-fitted with the second step 201, and the third step 202 on the bottom of the middle barrel 200 is snap-fitted with the fourth step 301 on the top of the lower barrel, thereby further reducing heat loss inside the heat field.
[0042] In this embodiment, the inner insulation barrel 6 and the outer insulation barrel 7 are made of graphite or carbon-carbon composite material, and the upper cover plate 11 and the lower cover plate 12 are made of carbon-carbon composite material to resist corrosion and thermal stress in the high temperature environment inside the thermal field.
[0043] In this embodiment, the filling thickness ratio of the inner insulation layer 8, the middle insulation layer 9 and the outer insulation layer 10 is 1:2:1, the inner insulation layer 8 is made of asphalt-based graphite soft felt or asphalt-based graphite carbonized felt, the middle insulation layer 9 is made of viscose-based graphite soft felt, and the outer insulation layer 10 is made of aerogel carbon fiber composite soft felt.
[0044] As an implementation method of this embodiment, the inner insulation layer 8 is made of four layers of asphalt-based graphite soft felt or asphalt-based graphite carbonized felt. The inner insulation layer 8 is not easy to age at high temperatures and has a low thermal conductivity, which effectively prevents the middle insulation layer 9 and the outer insulation layer 10 from aging, greatly reducing the number of times the insulation layer is replaced. The inner insulation layer only needs to be replaced when it ages, and there is no need to replace the inner and outer insulation barrels, which effectively extends the service life and reduces costs.
[0045] As an implementation method of this embodiment, the middle insulation layer 9 is formed by stacking seven layers of viscose-based graphite soft felt.
[0046] As an implementation method of this embodiment, the outer insulation layer 10 is made of four layers of aerogel carbon fiber composite soft felt. The outer insulation layer has a small thermal coefficient and can effectively reduce the heat loss in the single crystal furnace and reduce the power consumption of the single crystal furnace.
[0047] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.
Claims
1. A single crystal furnace thermal field structure, comprising a heat preservation component, wherein the heat preservation component is formed by overlapping an upper barrel (100), a middle barrel (200), and a lower barrel (300) in sequence from top to bottom, and a crucible (1) and a heater (2) are arranged inside the heat preservation component, characterized in that: The heater (2) is sleeved on the outside of the crucible (1), a guide tube (3) is connected to the top of the crucible (1), a hard felt (5) is arranged at the lower end of the heat preservation component, a receiving cavity is opened in the hard felt (5), a graphite electrode (4) is embedded in the receiving cavity, and the graphite electrode (4) is electrically connected to the heater (2); The upper barrel (100), the middle barrel (200), and the lower barrel (300) all include an inner insulation barrel (6), an outer insulation barrel (7), an upper cover plate (11), a lower cover plate (12), and an insulation layer completely filled between the inner insulation barrel (6) and the outer insulation barrel (7); the tops of the inner insulation barrel (6) and the outer insulation barrel (7) are respectively clamped with the two ends of the upper cover plate (11); and the bottoms of the inner insulation barrel (6) and the outer insulation barrel (7) are respectively clamped with the two ends of the lower cover plate (12); The bottom of the upper barrel (100) is clamped with the top of the middle barrel (200), and the bottom of the middle barrel (200) is clamped with the top of the lower barrel (300); The thermal insulation layer comprises an inner thermal insulation layer (8), a middle thermal insulation layer (9) and an outer thermal insulation layer (10) which are arranged in sequence from the inside to the outside.
2. The single crystal furnace thermal field structure according to claim 1, characterized in that: The inner insulation layer (8), the middle insulation layer (9) and the outer insulation layer (10) are fixed to the inner insulation barrel (6) by tying with a clamp; the outer insulation barrel (7) is fixed to the upper cover plate (11) and the lower cover plate (12) by carbon-carbon nails (55) respectively.
3. The single crystal furnace thermal field structure according to claim 2, characterized in that: The upper end of the inner heat-insulating barrel (6) is provided with a first stopper (51), and the upper end of the outer heat-insulating barrel (7) is provided with a second stopper (52); the upper cover plate (11) is respectively engaged with the first stopper (51) of the inner heat-insulating barrel (6) and the second stopper (52) of the outer heat-insulating barrel (7); the lower end of the inner heat-insulating barrel (6) is provided with a first step (53), and the lower end of the outer heat-insulating barrel (7) is provided with a third stopper (54); the lower cover plate (12) is respectively engaged with the first step (53) of the inner heat-insulating barrel (6) and the third stopper (54) of the outer heat-insulating barrel (7).
4. The single crystal furnace thermal field structure according to claim 1, characterized in that: The inner side of the top of the middle barrel (200) is provided with a second step (201), the outer side of the bottom of the middle barrel (200) is provided with a third step (202), the inner side of the top of the lower barrel (300) is provided with a fourth step (301), the outer side of the bottom of the upper barrel (100) is snap-fitted with the second step (201), and the third step (202) at the bottom of the middle barrel (200) is snap-fitted with the fourth step (301) at the top of the lower barrel.
5. The single crystal furnace thermal field structure according to claim 1, characterized in that: The inner heat-insulating barrel (6) and the outer heat-insulating barrel (7) are made of graphite or a carbon-carbon composite material.
6. The single crystal furnace thermal field structure according to claim 1, characterized in that: The upper cover plate (11) and the lower cover plate (12) are made of a carbon-carbon composite material.
7. The single crystal furnace thermal field structure according to claim 1, characterized in that: The filling thickness ratio of the inner thermal insulation layer (8), the middle thermal insulation layer (9) and the outer thermal insulation layer (10) is 1:2:
1.
8. The single crystal furnace thermal field structure according to claim 6, characterized in that: The material of the inner thermal insulation layer (8) is asphalt-based graphite soft felt or asphalt-based graphite carbonized felt.
9. The single crystal furnace thermal field structure according to claim 6, characterized in that: The middle thermal insulation layer (9) is made of viscose-based graphite soft felt.
10. The single crystal furnace thermal field structure according to claim 6, characterized in that: The outer thermal insulation layer (10) is made of aerogel carbon fiber composite soft felt.