Visual descending furnace

Abstract

This utility model relates to a descending furnace, comprising a frame, furnace body, heating components, insulation cover, rotary lifting mechanism, sealing mechanism, crucible, and laser. The furnace body includes a furnace bottom, furnace cylinder, and furnace cover. The furnace cylinder and insulation cover are made of heat-resistant transparent optical material. The sealing mechanism is installed between a through hole and a drive shaft, and includes a flexible section configured to shorten as the drive shaft rises and extend as the drive shaft descends. An evacuation port is provided on the sealing mechanism. By employing an insulation cover and furnace cylinder made of heat-resistant transparent optical material, real-time visual monitoring of the entire crystal growth process is achieved. The sealing mechanism maintains a stable vacuum environment in the heating chamber, effectively suppressing heat loss caused by thermal radiation and convection. The laser beam promotes the nucleation and directional growth of crystal materials through light-induced effects, and simultaneously enables in-situ observation and diagnosis of solid-liquid interface morphology, interface fluctuations, and internal crystal defects.

Description

Technical Field

[0001] This utility model relates to the field of lowering furnace technology, specifically to a visual lowering furnace. Background Technology

[0002] In artificial crystal material growth technology, the crucible descent method is an important crystal growth method. This method involves placing the crystal growth material in a crucible, which is then slowly lowered within a furnace. As it passes through the heating zone, the material gradually melts; as the crucible continues to descend, the bottom temperature first drops below the melting point and crystallization begins, with the crystal continuously growing as the crucible descends.

[0003] Currently, this technology generally suffers from the following problems: First, the crucible is usually placed inside the heater and an opaque insulation system, making it impossible to directly observe the actual state of raw material melting and crystallization throughout the crystal growth process. This not only makes it difficult to optimize process parameters and improve crystal quality but also limits the application of this technology in teaching demonstrations, hindering its promotion and popularization. Second, the insulation performance of existing descending furnaces is often poor, resulting in significant heat loss, uneven temperature distribution within the furnace, and low gradient control precision. This, in turn, affects the stability of crystal nucleation and growth, ultimately limiting the size and quality of the crystal.

[0004] To address these issues, some researchers have used transparent quartz tubes as insulation sleeves and plated them with gold to enhance insulation. However, the gold plating still obstructs light transmission to some extent, affecting direct observation of the melting and crystallization processes inside the furnace, thus limiting the improvement in visualization. Utility Model Content

[0005] The purpose of this invention is to provide a novel visual lowering furnace, which has good visibility and excellent heat preservation effect.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] This utility model provides a visually controlled lowering furnace, comprising:

[0008] frame;

[0009] A furnace body is mounted on the frame. The furnace body has an internal chamber, which includes a furnace bottom, a furnace cylinder, and a furnace cover. The furnace cylinder is made of heat-resistant transparent optical material, and a vacuum chamber and / or a circulating cooling chamber are provided inside the furnace cylinder. The furnace bottom has a through hole.

[0010] A heating assembly is disposed within the receiving cavity, the heating assembly comprising an upper heater and a lower heater;

[0011] A heat insulation cover is disposed in the receiving cavity. The heat insulation cover is made of heat-resistant transparent optical material. It is a single-layer structure or includes a multi-layer structure with interlocking layers. The heat insulation cover covers the outer periphery of the heating component and forms a heating cavity with the furnace bottom.

[0012] A rotary lifting mechanism is installed on the frame, and the drive shaft of the rotary lifting mechanism passes through a through hole on the furnace bottom and extends into the heating chamber;

[0013] A sealing mechanism, installed between the through hole and the drive shaft, is used to achieve a dynamic seal between the two. The sealing mechanism includes a flexible section configured to shorten as the drive shaft rises and extend as the drive shaft descends. The sealing mechanism has an extraction port connected to a vacuum system.

[0014] A crucible is disposed inside the heating chamber. The crucible is connected to the drive shaft and is controlled by the drive shaft to perform lifting and rotating movements.

[0015] In some embodiments, the flexible section is a corrugated pipe.

[0016] In some embodiments, the sealing mechanism further includes an upper sealing sleeve and a lower sealing sleeve. The upper sealing sleeve is fixedly installed below the furnace bottom, and the lower sealing sleeve is installed on the outer periphery of the drive shaft via a bearing mechanism. The flexible section is sealingly connected between the upper sealing sleeve and the lower sealing sleeve, and the exhaust port is opened on the upper sealing sleeve. Preferably, the sealing mechanism further includes one or more sealing elements disposed between the furnace bottom and the upper sealing sleeve, and one or more sealing elements disposed between the lower sealing sleeve and the drive shaft.

[0017] In some embodiments, the furnace cylinder includes at least two concentrically arranged furnace tubes, the inner one being the inner furnace tube and the outer one the outer furnace tube, forming the vacuum chamber or the circulating cooling chamber between the inner and outer furnace tubes. Preferably, sealing rings are provided at the connections between the inner furnace tube, the outer furnace tube, and the furnace bottom and furnace cover.

[0018] In some embodiments, the drive shaft has a hollow structure in which a central temperature sensor is installed.

[0019] In some embodiments, the lowering furnace further includes a heat insulation plate disposed within the heating chamber and located between the upper heater and the lower heater, the heat insulation plate being made of a heat-resistant transparent optical material.

[0020] In some embodiments, the heat-resistant transparent optical material is quartz or glass.

[0021] In some embodiments, the descending furnace further includes a side temperature sensor disposed within the heating chamber and located inside the bottom of the upper heater.

[0022] In some embodiments, the furnace bottom has a water inlet communicating with the circulating cooling chamber, and the furnace cover has a water outlet communicating with the circulating cooling chamber.

[0023] In some embodiments, the lowering furnace further includes a plurality of tie rods connected between the furnace cover and the furnace bottom, the plurality of tie rods being evenly distributed around the outer periphery of the furnace cylinder.

[0024] In some embodiments, the descending furnace further includes a laser mounted on the upper part of the furnace cover, the laser being configured to emit a laser beam into the furnace body.

[0025] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art:

[0026] This invention utilizes a heat-insulating cover and furnace cylinder made of heat-resistant transparent optical materials to achieve in-situ, real-time visual monitoring of the entire crystal growth process. This allows operators to intuitively observe the complete dynamic changes from raw material melting and seed crystal induction to crystal growth, significantly improving the ability to accurately perceive and control the growth interface and crystallization state.

[0027] Meanwhile, the sealing mechanism maintains a stable vacuum environment in the heating chamber, effectively suppressing heat loss caused by thermal radiation and convection. While maintaining visibility, it ensures the thermal stability of the high-temperature field within the furnace, providing uniform and controllable thermal conditions for crystal growth. The insulation hood structure further confines heat within the heating chamber, improving thermal efficiency and reducing energy consumption. The vacuum chamber and / or circulating cooling chamber within the furnace cylinder reduce the temperature of the furnace exterior wall, enhancing the long-term reliability and safety of the system. Attached Figure Description

[0028] Figure 1 A simplified structural diagram of the descending furnace provided in Example 1;

[0029] Figure 2 for Figure 1 An enlarged schematic diagram of part A in the middle;

[0030] Among them, 1. rack;

[0031] 2. Furnace body; 21. Furnace bottom; 211. Through hole; 212. Water inlet; 22. Furnace cylinder; 221. Inner furnace tube; 222. Outer furnace tube; 223. Circulating cooling chamber; 23. Furnace cover; 231. Water outlet; 24. Sealing ring; 25. Tie rod;

[0032] 31. Upper heater; 32. Lower heater; 33. Heat insulation plate; 34. Heating frame; 35. Side temperature measuring instrument;

[0033] 4. Rotary lifting mechanism; 41. Drive shaft; 42. Center temperature measuring instrument;

[0034] 5. Sealing mechanism; 51. Upper sealing sleeve; 511. Air extraction port; 52. Lower sealing sleeve; 53. Bellows; 54. Sealing element;

[0035] 6. Crucible; 7. Laser. Detailed Implementation

[0036] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0037] In the description of the embodiments of this utility model, it should be understood that the terms "upper" and "lower," etc., indicate the orientation or positional relationship as described above. Figure 1 The orientations shown are defined as follows: the furnace cover 23 is positioned above and the frame 1 is positioned below. This is only for the purpose of describing the embodiments of this utility model and simplifying the description, and is not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the embodiments of this utility model.

[0038] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0039] In this embodiment of the invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0040] The following disclosure provides many different implementations or examples for different structures of the embodiments of the present invention. To simplify the disclosure of the embodiments of the present invention, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the embodiments of the present invention. Furthermore, reference numerals and / or reference letters may be repeated in different examples of the embodiments of the present invention; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0041] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings.

[0042] Example 1

[0043] A type of descending furnace, such as Figure 1 and Figure 2 As shown, it includes a frame 1, a furnace body 2, a heating assembly, a heat insulation cover, a rotary lifting mechanism 4, a sealing mechanism 5, and a crucible 6. The furnace body 2 is mounted on the frame 1 and has an internal receiving chamber. The furnace body 2 includes a furnace bottom 21, a furnace cylinder 22, and a furnace cover 23. The furnace cylinder 22 is made of a heat-resistant transparent optical material; for example, the heat-resistant transparent optical material can be quartz or high-temperature resistant glass. A vacuum chamber and / or a circulating cooling chamber 223 are provided inside the furnace cylinder 22. The furnace bottom 21 has a through hole 211. The heating assembly is disposed in the receiving chamber and includes an upper heater 31 and a lower heater 32. The heat insulation cover is disposed in the receiving chamber and is made of a heat-resistant transparent optical material. The heat insulation cover is a single-layer structure or contains multiple nested structures. When it is a multi-layer structure, a vacuum environment is preferably provided between adjacent layers to achieve the heat insulation requirements. The heat insulation cover covers the outer periphery of the heating assembly and, together with the furnace bottom 21, forms a heating chamber. A rotary lifting mechanism 4 is mounted on the frame 1, and its drive shaft 41 passes through a through hole 211 on the furnace bottom 21 and extends into the heating chamber. A crucible 6 is disposed within the heating chamber, connected to and coaxial with the drive shaft 41, and controlled by the drive shaft 41 to perform lifting and rotating movements. A sealing mechanism 5 is installed between the through hole 211 and the drive shaft 41 to achieve a dynamic seal between them. The sealing mechanism 5 includes a flexible section configured to shorten as the drive shaft 41 rises and extend as the drive shaft 41 falls. An extraction port 511 is provided on the sealing mechanism 5, which is connected to a vacuum system to extract gas from the heating chamber, thereby maintaining a stable vacuum environment within the heating chamber. In other embodiments, a specific protective gas medium can also be introduced into the heating chamber through the extraction port 511 to provide the necessary atmosphere for crystal growth under non-vacuum conditions.

[0044] Furthermore, the flexible section is a bellows 53. The bellows 53 possesses excellent axial flexibility and radial rigidity, effectively adapting to the combined displacement of the drive shaft 41 during lifting and lowering while maintaining reliable sealing performance. Its corrugated structure is less prone to fatigue damage during extension and compression, resulting in a long service life and good dynamic response characteristics. As an example, the bellows 53 can be made of high-temperature alloys (such as nickel alloys), stainless steel, or other metal materials to meet the sealing requirements of different temperature environments and media conditions. Furthermore, the sealing mechanism 5 also includes an upper sealing sleeve 51 and a lower sealing sleeve 52; wherein, the upper sealing sleeve 51 is fixedly installed below the furnace bottom 21, and the lower sealing sleeve 52 is installed on the outer periphery of the drive shaft 41 via a bearing mechanism, allowing the drive shaft 41 to rotate freely relative to the lower sealing sleeve 52 and the sealing mechanism 5 as a whole. The flexible section is sealed between the upper sealing sleeve 51 and the lower sealing sleeve 52, and the exhaust port 511 is opened on the upper sealing sleeve 51. Preferably, the sealing mechanism 5 further includes one or more sealing elements 54 disposed between the furnace bottom 21 and the upper sealing sleeve 51, and one or more sealing elements 54 disposed between the lower sealing sleeve 52 and the drive shaft 41, to further enhance the sealing performance. The sealing elements 54 include, but are not limited to, O-rings, metal spiral wound gaskets, or flexible graphite gaskets, and can be selected according to the operating temperature and atmosphere of the sealing location. For example, nickel-based alloys, stainless steel, or flexible graphite can be used.

[0045] The furnace cylinder 22 includes at least two concentrically arranged furnace tubes: an inner furnace tube 221 located on the inner side and an outer furnace tube 222 located on the outer side. A vacuum chamber or circulating cooling chamber 223 is formed between the inner furnace tube 221 and the outer furnace tube 222. In this embodiment, the circulating cooling chamber 223 is formed between the inner furnace tube 221, the outer furnace tube 222, the furnace cover 23, and the furnace bottom 21. The water inlet 212 of the circulating cooling chamber 223 is located on the furnace bottom 21, and the water outlet 231 is located on the furnace cover 23. Sealing rings 24 are provided at the connection points between the inner furnace tube 221 and the outer furnace tube 222 and the furnace bottom 21 and the furnace cover 23, respectively. The material of the sealing rings 24 is the same as that of the sealing element 54 described above. In addition, the furnace body 2 also includes multiple tie rods 25 connected between the furnace cover 23 and the furnace bottom 21. The multiple tie rods 25 are evenly distributed around the outer circumference of the furnace cylinder 22. The advantages of setting up tie rods 25 are as follows: First, it can enhance the rigidity and stability of the overall structure of the furnace body 2, effectively resisting the stress caused by high-temperature thermal deformation and the internal vacuum environment; Second, it can prevent the furnace cover 23 and the furnace bottom 21 from relative displacement or deformation during the thermal cycle, ensuring the reliability of the sealing of the furnace body 2; Third, the evenly distributed tie rods 25 help maintain the concentricity of the furnace cylinder 22 and the internal insulation structure, providing a more stable thermal environment for crystal growth.

[0046] The heating assembly also includes a heating frame 34 disposed within the heating chamber, and a heater can be connected to the heating frame 34, through which the growth of the crystal within the crucible 6 can be observed. Furthermore, a heat insulation plate 33 is disposed between the upper heater 31 and the lower heater 32, and the heat insulation plate 33 is preferably made of a heat-resistant transparent optical material.

[0047] The specific structure of the rotary lifting mechanism 4 can be referred to the prior art. As an example, it includes a rotary motor and a lifting drive assembly, with the rotary motor mounted on the lifting drive assembly. The lifting drive assembly includes a lifting drive device and a drive shaft 41 connected to the output end of the lifting drive device. During crystal growth, the lifting drive device controls the drive shaft 41 to move the crucible 6 up and down synchronously, while the rotary motor controls the drive shaft 41 to rotate the crucible 6. The drive shaft 41 has a hollow structure, within which a central temperature measuring instrument 42 is installed. To further monitor the temperature of other areas within the furnace body 2, a side temperature measuring instrument 35 can also be installed on the inner bottom side of the upper heater 31.

[0048] The crucible 6 can be made of quartz, ceramic, metal or graphite, and its shape can refer to existing technology.

[0049] The descending furnace also includes a laser 7 mounted on the upper part of the furnace cover 23, which is configured to emit a laser beam into the furnace body 2. On the one hand, the laser beam can accurately irradiate the solid-liquid crystallization interface inside the crucible 6, promoting the nucleation and directional growth of the crystal material through photo-induced effects, effectively improving the crystallization quality and growth rate. On the other hand, by utilizing the transmission, scattering, or diffraction characteristics of the laser, in-situ observation and diagnosis of solid-liquid interface morphology, interface fluctuations, and internal crystal defects can be achieved, providing a basis for real-time control of process parameters, thereby further improving the uniformity and integrity of the crystal material.

[0050] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.

Claims

1. A visually controlled lowering furnace, characterized in that, include: Rack (1); A furnace body (2) is installed on the frame (1). The furnace body (2) has a receiving chamber inside, which includes a furnace bottom (21), a furnace cylinder (22) and a furnace cover (23). The furnace cylinder (22) is made of heat-resistant transparent optical material, and a vacuum chamber and / or a circulating cooling chamber (223) are provided inside the furnace cylinder (22). The furnace bottom (21) has a through hole (211). A heating assembly is disposed within the receiving cavity, the heating assembly comprising an upper heater (31) and a lower heater (32); A heat insulation cover is provided in the receiving cavity. The heat insulation cover is made of heat-resistant transparent optical material. It is a single-layer structure or includes a multi-layer structure that is nested with each other. The heat insulation cover is placed on the outer periphery of the heating component and surrounds the furnace bottom (21) to form a heating cavity. A rotary lifting mechanism (4) is installed on the frame (1). The drive shaft (41) of the rotary lifting mechanism (4) passes through the through hole (211) on the furnace bottom (21) and extends into the heating chamber. A sealing mechanism (5) is installed between the through hole (211) and the drive shaft (41) to achieve a dynamic seal between the two. The sealing mechanism (5) includes a flexible section configured to shorten as the drive shaft (41) rises and extend as the drive shaft (41) falls. An air extraction port (511) is provided on the sealing mechanism (5) and is connected to a vacuum system. A crucible (6) is disposed in the heating chamber. The crucible (6) is connected to the drive shaft (41) and is controlled by the drive shaft (41) to perform lifting and rotating actions.

2. The visual lowering furnace according to claim 1, characterized in that, The flexible section is a corrugated pipe (53).

3. The visual lowering furnace according to claim 1 or 2, characterized in that, The sealing mechanism (5) further includes an upper sealing sleeve (51) and a lower sealing sleeve (52). The upper sealing sleeve (51) is fixedly installed below the furnace bottom (21). The lower sealing sleeve (52) is installed on the outer periphery of the drive shaft (41) through a bearing mechanism. The flexible section is sealed between the upper sealing sleeve (51) and the lower sealing sleeve (52). The exhaust port (511) is opened on the upper sealing sleeve (51).

4. The visual lowering furnace according to claim 3, characterized in that, The sealing mechanism (5) further includes one or more sealing elements (54) disposed between the furnace bottom (21) and the upper sealing sleeve (51); And / or, the sealing mechanism (5) further includes one or more seals (54) disposed between the lower sealing sleeve (52) and the drive shaft (41).

5. The visual lowering furnace according to claim 1, characterized in that, The furnace tube (22) includes at least two concentrically arranged furnace tubes, the inner one being the inner furnace tube (221) and the outer one being the outer furnace tube (222). The vacuum chamber or the circulating cooling chamber (223) is formed between the inner furnace tube (221) and the outer furnace tube (222).

6. The visual lowering furnace according to claim 5, characterized in that, Sealing rings (24) are provided at the connection points of the inner furnace tube (221), the outer furnace tube (222), the furnace bottom (21), and the furnace cover (23).

7. The visual lowering furnace according to claim 1, characterized in that, The drive shaft (41) has a hollow structure, in which a central thermometer (42) is installed.

8. The visual lowering furnace according to claim 1, characterized in that, The lowering furnace also includes a heat insulation plate (33) disposed in the heating chamber and located between the upper heater (31) and the lower heater (32), the heat insulation plate (33) being made of a heat-resistant transparent optical material; And / or, the heat-resistant transparent optical material is quartz or glass; And / or, the lowering furnace also includes a side temperature measuring instrument (35) disposed in the heating chamber and located inside the bottom of the upper heater (31).

9. The visual lowering furnace according to claim 1, characterized in that, The furnace bottom (21) has a water inlet (212) that communicates with the circulating cooling chamber (223), and the furnace cover (23) has a water outlet (231) that communicates with the circulating cooling chamber (223).

10. The visual lowering furnace according to claim 1, characterized in that, The lowering furnace also includes a plurality of tie rods (25) connecting the furnace cover (23) and the furnace bottom (21), and the plurality of tie rods (25) are evenly distributed around the outer periphery of the furnace cylinder (22); And / or, the lowering furnace also includes a laser (7) mounted on the upper part of the furnace cover (23), the laser (7) being configured to emit a laser beam into the furnace body (2).

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