An air-smelted fused quartz ingot and its high-purity quartz sand melting process

Abstract

The present invention discloses a gas-smelted quartz glass ingot and a high-purity quartz sand melting process. When preparing the gas-smelted quartz glass ingot, a plurality of uniformly arranged flames react with the fed quartz sand through the combustion of hydrogen and oxygen in a deposition furnace to generate silicon dioxide particles, and the silicon dioxide particles are gradually deposited on a rotating quartz glass target to form the gas-smelted quartz glass ingot, and the flatness of the gas-smelted quartz glass ingot is less than 0.05 mm. The high-purity quartz sand melting process consists of the following technological steps carried out in sequence: preheating the deposition furnace, gradually raising the quartz glass target to a set height; feeding the quartz sand raw material into the raw material feeding port, and simultaneously introducing a mixed gas of hydrogen and oxygen through a quartz flame burner to carry the quartz sand raw material into the deposition furnace and deposit it on the quartz glass target; after growing to a set thickness, stop feeding and shut down the device; after natural cooling, remove the grown gas-smelted quartz glass ingot from the deposition furnace. The present invention realizes uniform combustion and reduces the waste of gas supply.

Description

Technical Field

[0001] The invention relates to the manufacture of glass, mineral or slag wool, and particularly to a gas-refined quartz glass ingot and a high-purity quartz sand melting process thereof. Background Art

[0002] Quartz glass is known as the "King of Glass" in the industry. It is made of natural crystalline quartz (crystal or high-purity silica) or silicon compounds and is melted at high temperature in a clean environment. Quartz glass originated abroad. In the 1950s, with the surge in the use of quartz glass in semiconductor technology and new electric light sources, the quartz glass industry began to develop. Quartz glass has a series of excellent physical and chemical properties, including extremely low thermal expansion coefficient, excellent temperature resistance, good chemical stability, excellent electrical insulation, low and stable ultrasonic delay, optimal ultraviolet, visible light and near-infrared spectral transmittance, and higher mechanical properties than ordinary glass. The above advantages can be used to make quartz glass ingots, tubes, rods, plates, crucibles, various utensils and devices, as well as quartz glass fibers and fabrics. These products are widely used in various high-tech product production process environments that require high temperature, cleanliness, corrosion resistance, light transmission, filtering, etc., such as aerospace, nuclear laser, semiconductor, optical communication, metallurgy, chemical industry, electric light source and other industries.

[0003] At present, the semiconductor industry is the main application field of quartz glass materials, and other directions mainly include photovoltaics, optical fiber communications and electric light sources. In terms of growth rate, semiconductors and photovoltaics have a higher growth rate and are the main growth engines of the current quartz glass market. It is expected that the market share will further expand in the future. In this regard, quartz glass materials and products such as quartz drawn tubes, quartz ingots and quartz crucibles have also ushered in new development space and opportunities.

[0004] The quartz tube, quartz ingot and quartz crucible are different in the melting of high-purity quartz sand, and the requirements for high-purity quartz sand raw materials are different. The operation method of gas refining to melt transparent quartz glass is to supply gas fuel hydrogen and oxygen to the gas refining lathe quartz blowtorch to ignite a flame to spray and melt natural crystal powder, and use a one-time gas refining molding process to make quartz glass pipes and utensils. Gas-refined quartz glass ingots are also made by this method. Quartz glass ingots are generally used for low-temperature materials, and low-temperature materials are more considered gas-melted quartz glass.

[0005] The paper "Brief Introduction to the Process of Melting Quartz Glass by Gas Refining with Low-pressure Operation" published by Huzhou Quartz Glass Factory in "Glass" improved the burner nozzle. It adopted a three-oxygen valve, and for the structural form of each channel, the stainless steel fine inlet pipe was connected to the end of the quartz base rod with a rubber fine pipe. The process was to first burn the head of the base rod, blow small bubbles, add materials, burn repeatedly and then add materials again. The trolley moved backward and was shaped by the support plate while blowing air, then burn and add materials again... until transparent quartz glass tubes or vessels with a predetermined length and diameter were produced. For gas-refined quartz glass ingots, the prior art generally used a flat or arc-shaped deposition substrate, which was different from growing on the base rod and shaping by moving the support plate of the trolley. No technical solution was found in the prior art to improve the burner nozzle in the gas-refining and melting preparation process of quartz glass ingots to achieve uniform combustion.

[0006] The patent with the publication number CN104926088B: A method for preparing a highly uniform synthetic quartz glass ingot uses a concave deposition pool to replace the flat or arc-shaped deposition substrate in the prior art, thereby avoiding the requirement of a temperature gradient on the deposition ingot surface during the deposition process and ensuring the stable formation of the quartz glass ingot; on this basis, the temperature of the furnace chamber and the entire deposition ingot surface can be increased, especially the temperature at the edge of the deposition ingot surface, reducing or eliminating the temperature gradient on the ingot surface, making the temperature distribution on the ingot surface uniform and consistent. Then, the silicon dioxide particles formed by chemical vapor synthesis are deposited in the concave deposition pool and continue to melt and diffuse at a higher temperature and a more uniform temperature field, thereby improving the uniform distribution of components such as hydroxyl groups in the quartz glass along the radial and axial directions, and thus improving the structural uniformity of the quartz glass. In order to reduce the temperature gradient on the deposition surface during the deposition process and control the deposition temperature of the deposition surface, an auxiliary heating device is arranged in a circle around the deposition pool in the deposition furnace chamber. However, for the setting of the auxiliary heating device to make the temperature rise uniformly at different positions on the edge of the deposition ingot surface, an isolation structure needs to be set again (just as it sets a circle of furnace lining). Otherwise, it is difficult to ensure uniform heat transfer, but this will undoubtedly increase the power consumption. However, if directly heating the quartz glass ingot by a resistance heating wire or other auxiliary heating devices, it is difficult to control the influence of the auxiliary heating device on the quartz glass ingot.

[0007] Patent with publication number CN113683291A: A method for producing large-sized and highly uniform synthetic quartz glass ingots. By increasing the number of burners and testing the temperature of the deposition surface, the uniformity of the deposition surface temperature is ensured, thereby significantly reducing the temperature gradient of the deposition surface (less than or equal to 10 °C). The pressure inside the deposition furnace is controlled by a slight negative pressure, reducing the risk of adhesion between the top burner and the furnace body. The airflow control inside the furnace is relatively stable, and the production efficiency is significantly improved. By increasing the dynamic monitoring of the deposition surface temperature, the temperature distribution of the deposition surface is monitored in real time, and the ratio of hydrogen and oxygen in different layers of the burner is dynamically adjusted to ensure the uniformity of the deposition temperature. However, it requires an increase in the number of burners and a significant number of test points for the deposition surface temperature test, resulting in a complex overall device structure and high costs. Summary of the Invention

[0008] The object of the present invention is to overcome the defects existing in the prior art and provide a gas-smelted quartz glass ingot. By improving the burner nozzle, a single central flame of the quartz flame burner during the original preparation is changed into multiple evenly distributed flames, achieving uniformity from the burner to better realize deposition uniformity, which is of great help in reducing or eliminating the temperature gradient on the ingot surface.

[0009] To achieve the above object, the technical solution of the present invention is to design a gas-smelted quartz glass ingot. During the preparation of the gas-smelted quartz glass ingot, a plurality of evenly arranged flames react with the fed quartz sand through the combustion of hydrogen and oxygen in the deposition furnace to generate silicon dioxide particles. The silicon dioxide particles are gradually deposited on the rotating quartz glass target to form a gas-smelted quartz glass ingot, and the flatness of the gas-smelted quartz glass ingot is less than 0.05 mm. By improving the burner nozzle, a single central flame of the quartz flame burner during the original preparation is changed into multiple evenly distributed flames, achieving uniformity from the burner to better realize deposition uniformity, which is of great help in reducing or eliminating the temperature gradient on the ingot surface.

[0010] A further technical solution is that the density of the gas-smelted quartz glass ingot is 2.2 - 2.3 g / cm 3 ³, the softening point temperature is 1700 ± 30 °C, the visible light transmittance is above 93%, in the ultraviolet spectral region, the maximum transmittance is above 80%, the Mohs hardness is 7, the silicon dioxide content is 99.997%, the weight is 50 - 80 kg, the diameter is 450 - 750 mm, and the height is 100 - 200 mm; the optical uniformity is 1.0 - 4.0 × 10 -6 .

[0011] The technical solution provided by the present invention also includes a high-purity quartz sand melting process for a gas-smelted quartz glass ingot, which consists of the following technological steps carried out in sequence:

[0012] S1: Start the heating device of the deposition furnace to preheat the deposition furnace, and gradually raise the quartz glass target to the set height;

[0013] S2: Feed the quartz sand raw material into the raw material feed inlet, and at the same time, introduce a mixed gas of hydrogen and oxygen through a quartz flame burner to carry the quartz sand raw material into the deposition furnace and deposit it on the quartz glass target;

[0014] S3: In the deposition furnace, melt the uniformly fed quartz sand raw material so that it slowly deposits on the surface of the quartz glass target. When the material surface rises due to the melting and deposition growth of the quartz sand, the quartz glass target gradually descends, and a gas-smelted quartz glass ingot is gradually formed;

[0015] S4: After growing to the set thickness, stop feeding and turn off the quartz flame burner and the heating device, and keep the quartz glass target rotating;

[0016] S5: After natural cooling, remove the grown gas-smelted quartz glass ingot from the deposition furnace;

[0017] The intake pipes of the aforementioned quartz flame burner are provided with several pieces, and the intake pipes are arranged in an annular array with the rotation axis of the barrel-shaped body of the quartz flame burner. One of every two oppositely arranged intake pipes serves as an oxygen intake pipe and the other serves as a hydrogen intake pipe; a flame distribution plate is provided at the middle position of the barrel-shaped body of the quartz flame burner, and through holes are arranged in an annular array on the flame distribution plate;

[0018] The deposition furnace includes a barrel-shaped body in the shape of a round barrel or a square barrel. The material of the furnace wall of the deposition furnace is a heat-insulating material. A groove is provided on the inner side wall of the lower half of the barrel-shaped body of the deposition furnace. A heating wire serving as an auxiliary heating mechanism is arranged at the middle position of the groove depth. A square-grooved rock wool board is fixedly arranged at the notch of the groove, and the outer wall of the groove side of the square-grooved rock wool board is fixedly connected to the furnace bottom and the furnace wall of the deposition furnace

[0019] In the middle of the square groove-shaped rock wool board, a through circular opening is provided. At the circular opening, a rock wool frame strip arranged in a circular array in a radial shape and an annular rock wool frame strip located between the radial rock wool frame strips are provided. An air bag is fixedly connected in each space surrounded by the rock wool frame strip, the annular rock wool frame strip, and the circular opening. The outer wall of the air bag is hermetically connected to the surrounding rock wool frame strip, annular rock wool frame strip, or rock wool board. The temperature for preheating the deposition furnace cavity is 850°C to 1100°C, and the preheating time is not less than 24H. The flow rates of hydrogen and oxygen in the quartz flame burner are 200 to 400 L / min and 100 to 200 L / min respectively; the temperature gradient of the deposition surface is less than 20°C; the deposition surface temperature is 1300°C to 1800°C; the temperature of the inner wall of the deposition furnace body is raised to 1200°C to 1300°C, and the temperature of the quartz glass target is raised to 1800°C; the quartz glass target is in a groove shape and the angle between its side wall and bottom wall is 90° to 150°. The burner nozzle (i.e., the barrel-shaped body of the quartz flame burner) adopts an annular array orifice plate (i.e., through holes are arranged in an annular array on the flame distribution plate), ensuring that after hydrogen and oxygen are mixed, they are ejected from a number of evenly distributed through holes, ensuring that multiple evenly distributed flames are generated when hydrogen and oxygen burn (on the one hand, achieving uniform combustion and reducing waste of gas supply; on the other hand, expanding the flame and reducing the large temperature difference between the edge and the middle of the deposition ingot surface. By improving the burner nozzle, the uniformity of the deposition surface temperature can be ensured, and the increase in the number of burners and the number of deposition surface temperature measurement points in the prior art can be reduced; through the evenly distributed flames, the flatness and roughness of the gas-smelted quartz glass ingot formed by deposition are better, and the workload of subsequent rounding, milling, surface grinding, polishing, and buffing of the quartz glass blank can be reduced, and even some of the aforementioned subsequent processing procedures such as surface grinding or polishing can be appropriately reduced).

[0020] A further technical solution is that the heating device is composed of a main heating mechanism located at the air inlet of the quartz flame burner and an auxiliary heating mechanism located inside the barrel-shaped body wall of the deposition furnace; the auxiliary heating mechanism includes heating wires located inside the barrel-shaped body wall of the deposition furnace and an annular array orifice plate provided at the opening of the inner wall of the barrel-shaped body of the deposition furnace. The main heating mechanism can adopt heating coils and high-frequency power cabinets in the prior art. The main heating mechanism is used for preheating the deposition furnace before it starts to work. The setting of the auxiliary heating device makes the temperature rise uniformly at different positions on the edge of the deposition ingot surface. The glass quartz ingot is directly assisted in heating through the heating wires, and the influence of the auxiliary heating device on the quartz glass ingot is controlled in the form of an annular array orifice plate, making the heat transfer as uniform as possible. During the process of heat directly transferring to the furnace cavity, due to the setting of the annular array orifice plate, part of the heat is blocked, and part of the heat passes through the through holes of the annular array orifice plate and directly transfers to the furnace cavity. Therefore, there is a certain heat transfer action between the heat passing through the through holes, so the heat is relatively uniform.

[0021] A further technical solution is that there are two annular array orifice plates from the inside to the outside, and the two annular array orifice plates are arranged in a staggered manner. Since the two annular array orifice plates arranged inside and outside are arranged in a staggered manner, the heat generated by the heating wire can be transferred to the furnace cavity of the deposition furnace more evenly (because the heat generated by the heating wire is first transferred to the furnace cavity through the through holes on the outer annular array orifice plate, and due to the annular array orifice plate arranged in a staggered manner on the inner side, the heat transfer direction changes and they transfer to each other during the change process, making the heat transferred through the through holes on the inner annular array orifice plate more uniform, avoiding the problem of uneven heat when the heat generated by the heating wire directly passes through the through holes on one layer of the annular array orifice plate to the furnace cavity). The annular array orifice plate is made of a high-temperature resistant heat-insulating material, such as an inorganic heat-insulating material with high temperature resistance like rock wool. In this way, when the heat passes through the two annular array orifice plates, the heat transfer of different hole positions on the outer side is carried out first to ensure the uniformity of heat, and then when the heat is transferred to the furnace cavity through the inner hole positions, it is relatively uniform. The annular array orifice plate can also be made of a material with good heat transfer performance, but only one annular array orifice plate is provided, which is arranged on the outer side inside the wall of the barrel-shaped body, and a flat plate made of the same material is arranged on the inner side inside the wall of the barrel-shaped body. The distance between the flat plate and the annular array orifice plate is set much larger than the distance between the two annular array orifice plates made of a high-temperature resistant heat-insulating material. In this way, the heat is transferred to the furnace cavity through the inner flat plate, and the annular array orifice plate arranged on the relatively outer side inside the wall, on the one hand, makes the heat "mix" during the process of transferring from the outside to the inside, that is, transfer to each other, and on the other hand, using a material with good heat transfer performance also reduces the heat loss due to the setting of the annular array orifice plate.

[0022] The advantages and beneficial effects of the present invention are as follows: By improving the burner head of the original quartz flame burner, one central flame during the original preparation is changed into multiple evenly distributed flames, achieving uniformity at the burner to better achieve uniform deposition, which is of great help in reducing or eliminating the temperature gradient on the surface of the ingot.

[0023] The burner head (i.e., the barrel-shaped body of the quartz flame burner) adopts an annular array orifice plate (i.e., through holes are arranged in an annular array on the flame distribution plate), ensuring that after the hydrogen and oxygen are mixed, they are ejected from a number of evenly distributed through holes, ensuring that multiple evenly distributed flames are generated when the hydrogen and oxygen burn (on the one hand, achieving uniform combustion and reducing the waste of gas supply; on the other hand, expanding the flame and reducing the large temperature difference between the edge and the middle of the deposited ingot surface. By improving the burner head, the uniformity of the deposition surface temperature can be ensured, reducing the increased number of burners and the number of temperature measurement points on the deposition surface in the prior art; through the evenly distributed flames, the flatness and roughness of the gas-smelted quartz glass ingot formed by deposition are better, which can reduce the workload of subsequent processes such as rounding, milling, surface grinding, polishing, and even appropriately reduce the aforementioned subsequent processing processes such as surface grinding or polishing).

[0024] The main heating mechanism is used to preheat the deposition furnace before it starts working. The setting of the auxiliary heating device enables the temperatures at different positions on the edge of the deposition mass surface to rise evenly. The quartz glass mass is directly assisted in heating through heating wires, and the influence of the auxiliary heating device on the quartz glass mass is controlled in the form of an annular array orifice plate, making the heat transfer as uniform as possible. During the process of heat directly transferring to the furnace cavity, due to the setting of the annular array orifice plate, part of the heat is blocked, and part of the heat passes directly through the through-holes of the annular array orifice plate to transfer to the furnace cavity. Therefore, there is a certain heat transfer action among the heat passing through the through-holes, so the heat is relatively uniform.

[0025] Due to the misaligned setting of the two annular array orifice plates arranged inside and outside, the heat generated by the heating wires can be transferred to the furnace cavity of the deposition furnace more evenly (because the heat generated by the heating wires first transfers to the furnace cavity through the through-holes on the outer annular array orifice plate, and due to the misaligned inner annular array orifice plate, the heat transfer direction changes and transfers to each other during the change process, making the heat transferred through the through-holes on the inner annular array orifice plate relatively uniform and avoiding the problem of uneven heat when the heat generated by the heating wires directly transfers to the furnace cavity through the through-holes on one layer of the annular array orifice plate). Brief Description of the Drawings

[0026] Figure 1 is a schematic diagram of Embodiment 1 of the preparation device related to the high-purity quartz sand melting process for gas-smelted quartz glass masses of the present invention;

[0027] Figure 2 is Figure 1 a schematic diagram of the quartz flame burner in

[0028] Figure 3 is Figure 2 a top view of the flame distribution plate in

[0029] Figure 4 is Figure 1 a schematic diagram of the lower part of the deposition furnace in

[0030] Figure 5 is Figure 4 a schematic diagram of the left part of the deposition furnace in

[0031] Figure 6 is a schematic diagram of Embodiment 2 of the present invention;

[0032] Figure 7 is Figure 6 a schematic diagram of the lower half part in

[0033] Figure 8 is a schematic diagram of Embodiment 3 of the present invention;

[0034] Figure 9 is Figure 8Schematic diagram of the lower part in

[0035] Figure 10 is Figure 8 Exploded schematic diagram of the left part of the lower half of the deposition furnace in

[0036] Figure 11 is Figure 10 Left view of the rock wool board in

[0037] Figure 12 is Figure 11 Schematic diagram after removing the rock wool frame strip and the annular rock wool frame strip;

[0038] Figure 13 is Figure 11 Schematic diagram of the opening in

[0039] Figure 14 is Figure 10 Left view of the rotating plate in

[0040] Figure 15 is Figure 14 Schematic diagram showing the rock wool frame strip and the annular rock wool frame strip but removing the spokes;

[0041] Figure 16 Schematic diagram of Embodiment 4 of the present invention;

[0042] Figure 17 is Figure 16 Schematic diagram of the lower part of

[0043] Figure 18 is Figure 17 Schematic diagram of the torsion spring and its nearby components in

[0044] Figure 19 is Figure 18 Schematic diagram of the temperature change component in

[0045] Figure 20 is Figure 19 Top view of a section of the external part in

[0046] Figure 21 is Figure 20 Bottom view of a certain airbag and part of the external part in

[0047] In the figure: 1, deposition furnace; 2, quartz glass target; 3, raw material feed inlet; 4, quartz flame burner; 5, gas-smelted quartz glass ingot; 6, intake pipe; 7, flame distribution plate; 8, through hole; 9, heating wire; 10, annular array orifice plate; 11, exhaust port; 12, column; 13, annular groove; 14, connecting shaft; 15, reduction motor; 16, groove; 17, rock wool board; 18, rock wool frame strip; 19, annular rock wool frame strip; 20, air bag; 21, rotating plate; 22, rotating shaft; 23, spoke; 24, torsion spring; 25, internal part; 26, external part; 27, air bag. Detailed implementation manners

[0048] The following combines the drawings and embodiments to further describe the detailed implementation manners of the present invention. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0049] Embodiment 1: As Figures 1 to 5 shown (for the convenience of illustration, Figure 1 two annular array orifice plates are not shown in the figure), the present invention is a gas-smelted quartz glass ingot. When the gas-smelted quartz glass ingot 5 is prepared, a plurality of uniformly arranged flames react with the fed quartz sand in the deposition furnace 1 by burning hydrogen and oxygen to generate silicon dioxide particles, and the silicon dioxide particles are gradually deposited on the rotating quartz glass target 2 to form the gas-smelted quartz glass ingot 5. The flatness of the gas-smelted quartz glass ingot 5 is less than 0.05 mm. The density of the gas-smelted quartz glass ingot 5 is 2.2 - 2.3 g / cm 3 , the softening point temperature is 1700 ± 30 °C, the visible light transmittance is above 93%, in the ultraviolet spectral region, the maximum transmittance is above 80%, the Mohs hardness is 7, the silicon dioxide content is 99.997%, the weight is 50 - 80 kg, the diameter is 450 - 750 mm, and the height is 100 - 200 mm; the optical uniformity is 1.0 - 4.0×10 -6 .

[0050] A high-purity quartz sand melting process for a gas-smelted quartz glass ingot 5 consists of the following technological steps carried out in sequence:

[0051] S1: Start the heating device of the deposition furnace 1 to preheat the deposition furnace 1, and gradually raise the quartz glass target 2 to the set height;

[0052] S2: Put the quartz sand raw material into the raw material feed inlet 3, and at the same time, introduce a mixed gas of hydrogen and oxygen through the quartz flame burner 4 to bring the quartz sand raw material into the deposition furnace 1 and deposit it on the quartz glass target 2;

[0053] S3: In the deposition furnace 1, melt the uniformly fed quartz sand raw material, and slowly deposit it on the surface of the fused silica target 2. When the material surface rises due to the molten deposition growth of the quartz sand, the fused silica target 2 gradually descends, and the gas-smelted fused silica ingot 5 is gradually formed;

[0054] S4: After growing to the set thickness, stop feeding and turn off the quartz flame burner 4 and the heating device, and keep the fused silica target 2 rotating;

[0055] S5: After natural cooling, remove the grown gas-smelted fused silica ingot 5 from the deposition furnace 1;

[0056] The intake pipe 6 of the aforementioned quartz flame burner 4 has four, and the intake pipes 6 are arranged in an annular array with the rotation axis of the barrel-shaped body of the quartz flame burner 4. One of the two relatively arranged intake pipes 6 serves as the oxygen intake pipe 6 and the other serves as the hydrogen intake pipe 6; a flame distribution plate 7 is provided at the middle position of the barrel-shaped body of the quartz flame burner 4, and through holes 8 are arranged in an annular array on the flame distribution plate 7. The heating device is composed of a main heating mechanism at the air inlet of the quartz flame burner 4 and an auxiliary heating mechanism in the barrel-shaped body wall of the deposition furnace 1; the auxiliary heating mechanism includes heating wires 9 in the barrel-shaped body wall of the deposition furnace 1 and an annular array orifice plate 10 arranged at the opening of the inner wall of the barrel-shaped body of the deposition furnace 1. There are two annular array orifice plates 10 from the inside to the outside, and the two annular array orifice plates 10 are arranged in a staggered manner (here, the staggering does not refer to the staggering of the two annular array orifice plates 10, but refers to the staggering of the through holes 8 on the two annular array orifice plates 10). There are two exhaust ports 11 on the side of the deposition furnace; a conical column 12 is fixedly connected under the fused silica target, and a conical hole is provided on the bottom wall of the deposition furnace for the lifting of the column 12; after such a setting, when the fused silica target rises, it is driven to rise by a lifting drive mechanism (a common technology, such as a reduction motor driving a lead screw nut mechanism to act, and the column rises through a slider fixedly connected to the nut, that is, the fused silica target rises), and when it descends, on the one hand, it is driven to descend by the lifting drive mechanism, and on the other hand, the conical hole adapted to the conical column can ensure that the bottom wall of the fused silica target is horizontal when the fused silica target descends to the final position (in order to ensure the uniformity of the molten deposition of the quartz sand, generally in addition to the lifting drive mechanism, a swing mechanism is also provided below the lifting drive mechanism. Therefore, in order to facilitate swinging while rising {or descending}, a conical hole is provided. In addition, the setting of the conical hole not only facilitates swinging without interference in lifting, but also can ensure the final position of the fused silica target). The mechanism for driving the column to rotate, that is, driving the fused silica target to rotate, can be a reduction motor. The output shaft of the reduction motor is fixedly connected concentrically with the column, and the reduction motor is fixedly connected to the slider.

[0057] Embodiment 2: The difference from Embodiment 1 is that, as Figure 6 、 Figure 7As shown (for the convenience of illustration, Figure 6 , Figure 7 only the reduction motor on the left side is shown), there is one annular array orifice plate 10. The barrel-shaped body wall of the deposition furnace has a hollow wall at the lower end in a circle. A heating wire 9 is arranged in the hollow part of the wall. Openings are arranged on the inner wall close to the furnace cavity. The annular array orifice plate 10 is rotatably arranged at the openings. The size of the openings is smaller than the size of the annular array orifice plate. A ring groove 13 is arranged on the inner wall close to the furnace cavity and extends outward around the openings for accommodating the annular array orifice plate. A shaft hole is arranged on the outer wall away from the furnace cavity. A connecting shaft 14 is rotatably and sealedly arranged with the shaft hole. The connecting shaft is fixedly connected to the center of the annular array orifice plate. The connecting shaft extends beyond the outer side of the outer wall away from the furnace cavity and is connected to the output shaft of the reduction motor 15. When making the gas-smelted quartz glass mass, the reduction motor is started and at the same time the auxiliary heating mechanism is started to make the temperatures at different positions on the edge of the deposition mass surface rise evenly. The rotating annular array orifice plate on the one hand reduces the direct heat transfer and power consumption, and on the other hand also ensures the uniform heat transfer. The auxiliary heating mechanism adopts an annular array orifice plate and rotates, enabling direct heat transfer, greatly reducing power consumption, and ensuring uniform heat transfer and that the temperature at the edge of the deposition mass surface reaches the requirement. (To better implement this embodiment, the original barrel-shaped deposition furnace body can be changed to a square barrel shape, and then four annular array orifice plates are arranged; or four annular array orifice plates are still arranged and a cylindrical deposition furnace body is adopted, but the heat transfer only occurs at the annular array orifice plates, and the inner walls at other positions of the deposition furnace are not connected to the furnace cavity, and the thickness of the annular array orifice plate is set to be smaller so that the square annular array orifice plate can rotate in the cylindrical deposition furnace body).

[0058] Embodiment 3: The difference from Embodiment 1 is that, as Figures 8 to 15 shown (for the convenience of illustration, Figure 8 , Figure 9 the reduction motor, the rotating shaft, and the rotating plate on the right side are not shown; Figure 14The rock wool frame strips and the annular rock wool frame strips are not shown), and the two exhaust ports 11 are connected to a negative pressure pump so that there is a certain negative pressure in the furnace chamber to avoid the quartz that has not fallen on the concave quartz glass target piece 2 from being deposited on the wall surface of the deposition furnace as much as possible; the barrel-shaped body of the deposition furnace 1 is a round barrel or a square barrel, and the wall of the deposition furnace is made of a heat-insulating material. The inner wall of the lower half of the barrel-shaped body of the deposition furnace 1 is provided with a groove 16, and the middle position of the groove depth of the groove 16 is provided with a heating wire 9 as an auxiliary heating mechanism, and a square groove-shaped rock wool board 17 is fixedly provided at the groove mouth of the groove, and the outer wall of the groove side of the square groove-shaped rock wool board 17 is fixedly connected to the bottom of the deposition furnace and the wall of the deposition furnace (that is, the bottom wall of the square groove-shaped rock wool board forms the furnace inner wall of the lower half of the barrel-shaped body of the deposition furnace 1). A through circular opening is provided in the middle, and radial rock wool frame strips 18 arranged in a circular array and annular rock wool frame strips 19 between the radial rock wool frame strips 18 are provided at the circular opening. An air bag 20 is fixedly connected in each space surrounded by the rock wool frame strips 18, the annular rock wool frame strips 19 and the circular opening, and the outer wall of the air bag 20 is sealed and connected with the surrounding rock wool frame strips 18, the annular rock wool frame strips 19 or the rock wool board 17 (to ensure that each space surrounded by the rock wool frame strips 18, the annular rock wool frame strips 19 and the circular opening is sealed); the vacuum degree of the gas in the air bag is different, and is divided into five different grades, namely, extremely high vacuum degree, relatively high vacuum degree, medium vacuum degree, relatively low vacuum degree, and extremely low vacuum degree, and the vacuum degrees of adjacent air bags 20 are different. A rotating plate 21 is arranged at a position of the square groove-shaped rock wool board 17 relative to the outside of the furnace cavity but located on the inside of the heating wire. A penetrating circular opening is also arranged on the rotating plate 21. The circular opening is provided with radial rock wool frame strips 18 arranged in an annular array and annular rock wool frame strips 19 located between the radial rock wool frame strips 18. An air bag is fixedly connected in each space surrounded by the rock wool frame strips 18, the annular rock wool frame strips 19 and the circular opening. The outer wall of the air bag is sealed and connected to the surrounding rock wool frame strips 18, the annular rock wool frame strips 19 or the rotating plate 21 (to ensure that each space surrounded by the rock wool frame strips 18, the annular rock wool frame strips 19 and the circular opening is sealed); the vacuum degree of the gas in the air bag is different, and is divided into five different grades, namely, extremely high vacuum degree, relatively high vacuum degree, medium vacuum degree, relatively low vacuum degree, and extremely low vacuum degree, and the vacuum degrees of adjacent air bags are different.On one side of the rotating plate 21 away from the furnace cavity, a number of spokes 23 fixedly connected at one end are provided. The other ends of the spokes 23 are fixedly connected to the edge of the rotating plate 21. The rotating shaft 22 is fixedly connected to the same end where the several spokes are fixedly connected. The connecting shaft extends beyond the outer side of the outer wall away from the furnace cavity and is connected to the output shaft of the reduction motor 15. After such a setting, when the production of the gas-smelted quartz glass ingot starts, the reduction motor is started and at the same time the auxiliary heating mechanism is started to make the temperatures of different positions on the edge of the deposited ingot surface rise evenly. Since the gas bag with a relatively high vacuum degree allows little heat transfer, and the gas bag with an extremely high vacuum degree allows even less heat transfer, while the gas bag with a relatively low vacuum degree or an extremely low vacuum degree can transfer part of the heat to avoid too strong heat insulation performance. The rotating rotating plate 21 cooperates with the fixedly arranged square-grooved rock wool board 17, so that the gas bags on the rotating plate and the gas bags on the square-grooved rock wool board 17 are always corresponding to gas bags with different vacuum degrees or in a situation where one inner gas bag corresponds to two outer gas bags. In this way, the heat transfer at different positions is different, and because the rotating plate is always rotating, the heat transfer at different positions and different times is also different. Through such a disordered process, the purpose of uniform heat transfer is achieved instead. The heat transfer is uniform and can ensure that the temperature of the edge of the deposited ingot surface reaches the requirement (the deposition furnace body can be in the shape of a square barrel, and then four square-grooved rock wool boards 17 are provided; or a circular barrel-shaped deposition furnace body can be used, and the bottom wall of the grooves of the four square-grooved rock wool boards 17 is a curved bottom, and it is a curved bottom imitating the deposition furnace body). And this method transfers heat to the furnace cavity of the deposition furnace at intervals (because the gas bag is not completely vacuum, so the heat transfer is relatively direct compared with the prior art), so the heat loss is small and the power consumption is low; and the heat transfer in the way of this embodiment is very uniform. Using the reverse idea, the method of making the heat transfer at each position and each time point different instead obtains the effect of uniform heat transfer.

[0059] Embodiment 4: The difference from Embodiment 2 is that, as Figures 16 to 21As shown in the figure, a torsion spring 24 made of silicone rubber is fixedly arranged on the inner wall away from the furnace cavity. The other end of the torsion spring is fixedly connected to the annular array orifice plate 10. A temperature change component is also fixedly arranged on the inner wall away from the furnace cavity to push the torsion spring 24 when the temperature rises to drive the rotation of the annular array orifice plate 10. The temperature change component includes a titanium-rich Ti-Ni shape memory alloy inner component 25 in an L shape and an outer component 26 wrapped around the outer periphery of the inner component 25 (the outer component can be made of a heat-insulating material such as rock wool board). The outer component 26 is used to block part of the heat (but also transfer a small amount of heat to ensure that the temperature environment of the inner component is the phase change temperature of the titanium-rich Ti-Ni shape memory alloy). The outer component 26 is composed of two hinged sections to deform along with the inner component 25 when the inner component deforms. A number of holes are arranged at intervals on each section of the outer component 26. At least two air bags 27 are arranged in sequence from the inside to the outside at the holes. The air bags 27 are made of heat-insulating materials, and the inside of the air bags 27 is high-vacuum gas or low-vacuum gas. In this way, the heat transferred by the two or more air bags arranged from the inside to the outside is isolated by the gas with a vacuum degree for the most part. And because the gases in the air bags from the inside to the outside are not all high-vacuum gases or extremely high-vacuum gases, part of the heat can still be transferred. In this way, the required temperature environment of the inner component can be achieved by setting the vacuum degree of the gas in the air bags. After such a setting, when the production of the gas-smelted quartz glass ingot starts, the auxiliary heating mechanism (i.e., the heating wire 9) is started simultaneously to make the temperatures at different positions on the edge of the deposited ingot surface rise evenly. The start of the auxiliary heating mechanism also makes the inner component 25 of the temperature change component reach the phase change temperature and deform (due to the setting of the air bags 27 on the outer component 26, only part of the heat is transferred to the inner component 25, so the temperature environment of the inner component 25 will not be too high basically, which ensures the normal operation of the phase change material inner component). Since the outer component is of a two-section hinged type, the outer component 26 also deforms accordingly. In this way, the torsion spring 24 is pushed by the temperature change component to make the annular array orifice plate 10 rotate. And after the torsion spring is stressed and rotates, it will have a certain degree of rebound. So the rotation range of the annular array orifice plate 10 gradually becomes smaller after several forward and reverse rotation cycles (equivalent to the attenuation of the operation situation). Finally, after the balance between the deformation force of the temperature change component and the torsion force of the torsion spring is achieved, the annular array orifice plate 10 stops rotating. And during the several forward and reverse rotation cycles of the annular array orifice plate 10, the heat of the heating wire 9 is also mixed when passing through the through holes on the annular array orifice plate 10 to transfer heat, making the transferred heat more uniform. The setting of this embodiment uses the temperature itself as the energy to drive the annular array orifice plate 10, without the need to additionally set a driving mechanism such as a reduction motor, etc. Fewer components are required, the cost of the whole process is lower, and the structure is more concise.

[0060] The silicone rubber spring has excellent high-temperature resistance and can be used for a long time in a high-temperature environment of 1500°C. Since the phase transition temperature of the titanium-rich Ti-Ni shape memory alloy is relatively high, specifically 80 - 110°C, and since the working temperature of the furnace chamber of the deposition furnace is 1300 - 1800°C, the auxiliary heating device is generally set below 1500°C. An outer member 26 covering the periphery of the inner member 25 is provided so that the inner member is thermally insulated to a large extent, reaching the phase transition temperature required by the inner member without exceeding too much (ensuring the normal temperature change and shape recovery of the inner member).

[0061] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A high-purity quartz sand melting process for gas-refined quartz glass ingots, characterized in that: It consists of the following process steps performed in sequence: S1: Start the heating device of the deposition furnace to preheat the deposition furnace, and gradually raise the quartz glass target to a set height; S2: Put the quartz sand raw material into the raw material feed port, and at the same time, introduce a mixed gas of hydrogen and oxygen through a quartz flame burner to bring the quartz sand raw material into the deposition furnace and deposit it on the quartz glass target sheet; S3: In the deposition furnace, the quartz sand raw material is melted at a uniform speed and slowly deposited on the surface of the quartz glass target. When the material surface rises due to the growth of the quartz sand melt deposition, the quartz glass target gradually descends, and the gas-refined quartz glass ingot is gradually formed; S4: After growing to the set thickness, stop feeding and turn off the quartz flame burner and heating device, and keep the quartz glass target rotating; S5: After natural cooling, the grown gas-refined quartz glass ingot is removed from the deposition furnace; The quartz flame burner is provided with a plurality of air inlet pipes, and the air inlet pipes are arranged in a circular array with the rotation axis of the barrel-shaped body of the quartz flame burner, and one of the two air inlet pipes arranged opposite to each other is used as an oxygen air inlet pipe and the other is used as a hydrogen air inlet pipe; a flame uniform distribution plate is provided in the middle of the barrel-shaped body of the quartz flame burner, and through holes are arranged in a circular array on the flame uniform distribution plate; The deposition furnace comprises a barrel-shaped or square barrel-shaped barrel-shaped body, the wall of the deposition furnace is made of heat-insulating material, the inner wall of the lower half of the barrel-shaped body of the deposition furnace is provided with a groove, the middle position of the groove depth of the groove is provided with a heating wire as an auxiliary heating mechanism, a square groove-shaped rock wool board is fixedly provided at the groove mouth, and the outer wall of the groove side of the square groove-shaped rock wool board is fixedly connected to the bottom of the deposition furnace and the wall of the deposition furnace; A circular opening is provided in the middle of the square groove-shaped rock wool board, and a circular array of radial rock wool frame bars and annular rock wool frame bars between the radial rock wool frame bars are provided at the circular opening. An air bag is fixedly connected in each space surrounded by the rock wool frame bars, the annular rock wool frame bars and the circular opening, and the outer wall of the air bag is sealed and connected to the surrounding rock wool frame bars, annular rock wool frame bars or rock wool boards; The heating device is composed of a main heating mechanism located at the air inlet of the quartz flame burner and an auxiliary heating mechanism located in the wall of the barrel-shaped body of the deposition furnace; the auxiliary heating mechanism also includes a ring array orifice plate arranged at the opening of the inner wall of the barrel-shaped body of the deposition furnace; A torsion spring is fixedly arranged on the inner wall away from the furnace cavity, and the other end of the torsion spring is fixedly connected to the annular array orifice plate. A temperature change component is also fixedly arranged on the inner wall away from the furnace cavity.

2. The high-purity quartz sand melting process for gas-refined quartz glass ingot according to claim 1, characterized in that: The torsion spring is made of silicone rubber; the temperature-variable component is used to push the torsion spring when the temperature rises to drive the annular array orifice plate to rotate; the temperature-variable component includes an L-shaped titanium-rich Ti-Ni shape memory alloy inner component and an outer component coated on the periphery of the inner component, the outer component is made of rock wool board, and the outer component is composed of two hinged sections so that when the inner component is deformed, the outer component also deforms accordingly, and each section of the outer component is provided with a plurality of holes arranged at intervals, and at least two air bags are arranged in sequence from the inside to the outside of the holes, and the air bags are made of heat-insulating material, and the air bags contain high vacuum gas or low vacuum gas.

3. A gas-refined quartz glass ingot prepared by the melting process as claimed in claim 1, characterized in that: When preparing the gas-refined quartz glass ingot, a plurality of evenly arranged flames react with the fed quartz sand in a deposition furnace through the combustion of hydrogen and oxygen to generate silicon dioxide particles. The silicon dioxide particles are gradually deposited on a rotating quartz glass target to form a gas-refined quartz glass ingot. The flatness of the gas-refined quartz glass ingot is less than 0.05 mm.

4. A gas-refined quartz glass ingot according to claim 3, characterized in that: The density of the gas-refined quartz glass ingot is 2.2-2.3 g / cm 3 , softening point temperature is 1700±30℃, visible light transmittance is above 93%, in the ultraviolet spectrum area, the maximum transmittance is above 80%, Mohs hardness is 7, silicon dioxide content is 99.997%, weight is 50~80kg, diameter is 450~750mm, height is 100~200mm; optical uniformity is 1.0~4.0×10 -6 .

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