A high-purity synthetic quartz sand purification device and purification method
Patent Information
- Application Number
- CN202611244917.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-17
- Publication Date
- 2026-10-23
AI Technical Summary
[0005]本发明提供一种高纯合成石英砂提纯装置，解决相关技术中石英砂提纯过程中加热元件与炉管存在相对运动导致局部过热、加热不均匀以及热应力变形的技术问题
[0016]本发明通过将炉体组件与炉管刚性连接并由同一旋转驱动组件同步驱动，使加热元件与炉管之间不存在相对运动，解决了现有提纯设备炉管内温度场不均匀的技术问题，取得了炉管周向各位置热辐射量一致、石英砂物料受热均匀、杂质充分气化脱附的技术效果。炉体组件与炉管之间无相对运动，消除了炉管外壁的相对摩擦，延长了炉管的使用寿命。旋转密封件仅设置于炉管端部法兰与机架静止部件之间，密封副数量减少，降低了密封失效风险。炉管内物料依靠重力自然翻滚实现均匀受热，无需在炉管内部设置搅拌结构，避免了高温下搅拌件析出金属杂质对石英砂物料造成二次污染。
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Figure CN122961174A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of quartz sand purification technology, and more specifically, to a high-purity synthetic quartz sand purification apparatus and purification method. Background Technology
[0002] High-purity synthetic quartz sand is a core raw material for photovoltaic silicon wafers, semiconductor quartz crucibles, and other fields, and high-temperature purification is a key process in its preparation. Existing purification equipment typically adopts a structure where the furnace body is fixed while the furnace tube rotates independently. The heating element is fixed with the furnace body, and the furnace tube rotates inside the heating element.
[0003] In this structure, the circumferential regions of the furnace tube alternately face the fixed heating element during rotation, resulting in an uneven temperature field distribution within the furnace tube, localized overheating of the quartz sand material, and incomplete removal of impurities. The relative motion between the furnace body and the furnace tube causes friction and stress deformation between the outer wall of the furnace tube and the inner wall of the furnace body, exacerbating furnace tube wear.
[0004] The aforementioned defects have led to technical problems in existing purification equipment, such as uneven temperature field inside the furnace tube and short service life of the furnace tube. Summary of the Invention
[0005] This invention provides a high-purity synthetic quartz sand purification device, which solves the technical problems in the related art of local overheating, uneven heating and thermal stress deformation caused by the relative movement between the heating element and the furnace tube during the quartz sand purification process.
[0006] This invention discloses a high-purity synthetic quartz sand purification device, comprising: frame; A furnace body assembly, wherein the furnace body assembly is a cylindrical shell structure, and a heating element for heating is fixed on the inner wall of the furnace body assembly; The furnace tube is coaxially inserted inside the furnace body assembly. The inner cavity of the furnace tube forms a quartz sand purification chamber. Both ends of the furnace tube are rigidly connected to the outer shell of the furnace body assembly through thermal compensation fixing devices. The thermal compensation fixing device is an eight-claw thermal compensation fixing device, which is a ring chuck structure, including an outer ring and an inner ring. The radial end face of the outer ring is fixedly connected to the end face of the furnace shell by bolts. The inner ring has eight claws. The eight claws radially tighten and clamp the end of the outer wall of the furnace tube. The axial sleeve of the outer ring is slidably sleeved on the outside of the inner ring. Eight fixing plates are fixed in a ring on the outer side wall of the inner ring. A V-shaped elastic metal sheet is fixed between each fixing plate and the radial end face of the outer ring. A rotary drive assembly is fixed to the frame and driven to the furnace shell, driving the furnace body assembly and the furnace tube to rotate synchronously around the same axis, so that there is no relative movement between the heating element and the furnace tube; A support and positioning assembly is disposed between the frame and the furnace shell to bear the radial load of the furnace assembly and the furnace tube and to constrain the axial position.
[0007] Furthermore, the outer layer of the furnace body assembly is the furnace shell, and an insulation layer is attached and fixed to the inner wall of the furnace shell. The heating element is fixed to the inner wall of the insulation layer. The heating element is a resistance wire arranged along the axis of the furnace tube, and the resistance wire is arranged around the outer wall of the furnace tube. The heating element is connected to an external power source through a conductive slip ring. The rotating ring of the conductive slip ring is fixed to the furnace shell, and the stationary ring of the conductive slip ring is fixed to the frame. The rotating ring maintains sliding conductive contact with the stationary ring through a brush.
[0008] Furthermore, the rotary drive assembly includes a variable frequency speed control motor and a synchronous transmission gear set. The body of the variable frequency speed control motor is fixed to the frame. The output shaft of the variable frequency speed control motor is fixedly connected to the drive gear of the synchronous transmission gear set. The drive gear of the synchronous transmission gear set meshes with a gear ring fixed to the outer surface of the furnace shell. The gear ring is an annular gear ring and is fixed to the outer circumference of the furnace shell by bolts and positioning pins.
[0009] Furthermore, the support and positioning assembly includes a rolling ring and support rollers. The rolling ring is an annular ring body, which is fixed to the outer circumferential surface of the furnace shell by bolts and positioning pins. The axle of the support roller is fixed to the frame by a bearing seat. The outer ring of the support roller has a groove that matches the rolling ring, and the outer circumferential surface of the groove makes rolling contact with the outer circumferential surface of the rolling ring. At least two sets of support rollers are provided, located on both sides of the furnace shell along the axial direction. Each set of support rollers includes two rollers, which are symmetrically distributed on both sides of the outer circumferential surface of the rolling ring along the circumference of the furnace shell, forming a V-shaped support.
[0010] Furthermore, flanges are installed at both ends of the furnace tube. The flanges are annular disc-shaped structures, which are detachably connected to the ends of the furnace tube by bolts and rotate synchronously with the furnace tube. A circular through hole is opened in the center of the flange, which passes through the flange and connects the inner cavity of the furnace tube with the external pipeline. A PTFE filter cloth is installed on the inner side of the flange, which seals the inner side of the circular through hole of the flange.
[0011] Furthermore, diaphragm valves and rotary joints are sequentially installed on the outer sides of the flanges at both ends of the furnace tube.
[0012] Furthermore, the stationary side sealing seat of the rotary joint is connected to the gas pipeline, the gas pipeline at the gas inlet end of the furnace tube is connected to the gas supply source, and the gas pipeline at the gas outlet end of the furnace tube is connected to the gas inlet of the vacuum pump.
[0013] Furthermore, a water-cooled inlet guide ring and a water-cooled return guide ring are also provided on the side wall of the furnace tube at the gas outlet end. A water-cooled water guide pipe that communicates with the water-cooled inlet guide ring and the water-cooled return guide ring is also provided inside the side wall of the furnace tube.
[0014] Furthermore, one end of the frame near the gas inlet of the furnace tube is hinged to the ground foundation via a hinge shaft, which extends along the width of the furnace tube. A lifting push rod is provided at the bottom of the other end of the frame. The fixed end of the lifting push rod is hinged to the ground foundation, and the top end of the push rod is hinged to the bottom of the frame. When the lifting push rod extends, it pushes the frame, causing the frame to tilt in the vertical plane around the hinge shaft, resulting in an angle of inclination of the furnace tube's axis relative to the horizontal plane. Under the influence of gravity, the material in the furnace tube's inner cavity slides along the axis towards the discharge end.
[0015] A method for purifying high-purity synthetic quartz sand includes the following steps: When in use, first fix the furnace tube to both ends of the furnace shell using the eight-claw thermal compensation fixing device, so that the furnace tube is coaxially inserted into the furnace body assembly. Fix the toothed ring and rolling ring to the outer circumference of the furnace shell using bolts and positioning pins. Hoist the furnace body assembly onto the support rollers of the frame, so that the rolling ring makes rolling contact with the wheel surface of the support rollers. The quartz sand material to be purified is fed into the quartz sand purification chamber from the feed end of the furnace tube. During the feeding process, the rotary drive component drives the furnace tube to rotate in the opposite direction, and the material shovel at the feed end feeds the material into the inner cavity of the furnace tube. After the material is loaded, the flange and PTFE filter cloth are installed at both ends of the furnace tube. The flange is then connected and fastened to the octagonal thermal compensation fixing device with bolts. Then, the diaphragm valve and rotary joint are installed in sequence, so that the static side sealing seat of the rotary joint is in contact with the dynamic sealing surface of the rotary joint on the outer end face of the flange to achieve a seal. The gas pipeline is then connected to the static side sealing seat of the rotary seal respectively. Start the variable frequency speed control motor. The output shaft of the variable frequency speed control motor drives the gear ring to rotate through the synchronous transmission gear set. The gear ring drives the furnace shell to rotate. The furnace shell drives the furnace tube to rotate synchronously through the eight-claw thermal compensation fixing device. The furnace body assembly and the furnace tube rotate around the same axis at the same speed. The heating element rotates with the furnace body assembly and there is no relative rotation between it and the furnace tube. The heating element is activated to raise the temperature to the process temperature and maintain it at a constant temperature. During the heat preservation and purification stage, the furnace tube rotates continuously. The quartz sand material in the inner cavity of the furnace tube tumbles under the action of gravity. The material particles are alternately exposed to the heating radiation to achieve uniform heating. At the same time, the vacuum pump is activated to evacuate the inner cavity of the furnace tube through the gas pipeline at the gas outlet, so that the quartz sand purification chamber is in a negative pressure state. The impurities in the quartz sand are vaporized and desorbed at high temperature. The negative pressure environment causes the impurity gas to be discharged from the discharge end along the airflow direction and then extracted by the vacuum pump. During the heat preservation and purification stage, process gas is simultaneously introduced into the inner cavity of the furnace tube through the gas pipeline at the feed end. The process gas flows along the axial direction across the surface of the material and is then extracted by the vacuum pump at the discharge end, forming a directional airflow that carries impurity gas out. After purification, heating is stopped. Once the temperature inside the furnace tube drops to the material collection temperature, the flange and rotary seal at the discharge end are removed. The lifting push rod is then activated to tilt the frame, creating an angle between the furnace tube axis and the horizontal plane. The rotary drive assembly drives the furnace tube to rotate in the forward direction. Under the influence of gravity and rotation, the material slides along the axis towards the discharge end and is discharged, completing the material collection process. After material collection is completed, the lifting push rod retracts to restore the frame to a horizontal state.
[0016] This invention solves the technical problem of uneven temperature field inside the furnace tube in existing purification equipment by rigidly connecting the furnace body assembly and the furnace tube and synchronously driving them with the same rotary drive assembly. This eliminates relative movement between the heating element and the furnace tube, achieving the technical effects of uniform heat radiation at all locations around the furnace tube, uniform heating of the quartz sand material, and complete vaporization and desorption of impurities. The absence of relative movement between the furnace body assembly and the furnace tube eliminates relative friction on the outer wall of the furnace tube, extending its service life. The rotary seal is only located between the flange at the end of the furnace tube and the stationary parts of the frame, reducing the number of sealing pairs and lowering the risk of seal failure. The material inside the furnace tube achieves uniform heating through natural tumbling due to gravity, eliminating the need for an internal stirring structure and preventing secondary contamination of the quartz sand material by metal impurities precipitated from the stirring components at high temperatures.
[0017] This invention improves the existing eight-claw chuck by designing an eight-claw thermal compensation fixing device. This device not only enables a rigid connection between the furnace tube and the furnace body, but also absorbs the thermal stress on the furnace tube through the deformation of the V-shaped elastic metal sheet when the furnace tube is heated and undergoes axial thermal stress deformation. This protects the furnace tube and can effectively prevent furnace explosion caused by thermal stress deformation. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the quartz furnace tube structure of the high-purity synthetic quartz sand purification device of the present invention; Figure 2 This is a schematic diagram of the structure of the furnace body assembly cover; Figure 3This is a schematic diagram of the installation process of hoisting the quartz furnace tube into the furnace body assembly; Figure 4 This is a schematic diagram of the furnace body components after the insulation cover, toothed ring, rolling ring and eight-claw chuck are installed; Figure 5 This is a schematic diagram of the preparation stage for filling quartz sand material into the furnace tube; Figure 6 This is a structural diagram showing the completed installation of flanges, PTFE filter cloth, and gas pipelines. Figure 7 This is a schematic diagram of the unloading stage after purification, in which the furnace body tilts and the furnace tubes rotate clockwise to collect the material. Figure 8 This is a side sectional view of the octagonal thermal compensation fixing device of the present invention; Figure 9 This is a front view of the octagonal thermal compensation fixing device of the present invention.
[0019] 1-Furnace tube; 2-Furnace body assembly; 201-Insulation layer; 202-Resistance wire; 3-Variable frequency speed control motor; 4-Drive gear; 5-Gear ring; 6-Rolling ring; 7-Supporting roller; 8-Flange; 9-PTFE filter cloth; 10-Diaphragm valve; 11-Rotary joint; 12-Gas pipeline; 13-Vacuum pump; 14-Water-cooled inlet guide slip ring; 15-Water-cooled return guide slip ring; 16-Hinged shaft; 17-Lifting push rod; 18-Octagonal thermal compensation fixing device; 1801-Outer ring; 1802-Inner ring; 1803-Claw; 1804-Fixing plate; 1805-V-shaped elastic metal sheet. Detailed Implementation
[0020] refer to Figures 1 to 9 This embodiment provides a high-purity synthetic quartz sand purification device, which is used to remove impurities from quartz sand in a high-temperature environment. The high-purity synthetic quartz sand purification device includes at least a frame, a furnace body assembly 2, a furnace tube 1, a rotary drive assembly, and a support and positioning assembly. The furnace tube 1 is coaxially inserted inside the furnace body assembly 2, and the inner cavity of the furnace tube 1 forms a quartz sand purification chamber. The rotary drive assembly simultaneously rotates the furnace body assembly 2 and the furnace tube 1 synchronously around the same axis. Heating elements are fixed to the inner wall of the furnace body assembly 2, and the heating elements are arranged around the outer wall of the furnace tube 1. Because the furnace body assembly 2 and the furnace tube 1 rotate synchronously, there is no relative movement between the heating elements and the furnace tube 1. The radiant heating position of the heating elements on the furnace tube 1 remains constant, and all areas around the furnace tube 1 always receive the same amount of thermal radiation.
[0021] The frame serves as the overall support reference and is a frame structure extending along the axis of furnace tube 1. The furnace body assembly 2 is mounted on the frame via a support and positioning assembly and can rotate freely around the axis of furnace tube 1.
[0022] Furnace assembly 2 is a cylindrical shell structure. The outer layer of furnace assembly 2 is the furnace shell, and an insulation layer 201 is fixedly attached to the inner wall of the furnace shell. Heating elements are fixed to the inner wall of the insulation layer 201. The heating elements are resistance wires 202, evenly arranged along the axis of the furnace tube 1, spiraling or forming multiple annular segments around the outer wall of the furnace tube 1. A gap is maintained between the heating elements and the outer wall of the furnace tube 1 for radiative heat transfer. The heating elements are connected to an external power source via a conductive slip ring. The rotating ring of the conductive slip ring is fixed to the furnace shell, and the stationary ring is fixed to the frame. The external power supply wire is connected to the stationary ring. The rotating ring maintains sliding conductive contact with the stationary ring through a brush, thereby continuously supplying power to the heating elements during the rotation of furnace assembly 2.
[0023] Furnace tube 1 is a cylindrical tube open at both ends, penetrating furnace body assembly 2 along its axial direction. The feed and discharge of furnace tube 1 are on the same side. Both ends of furnace tube 1 are fixedly connected to the furnace shell via an eight-claw thermal compensation fixing device 18. The eight-claw thermal compensation fixing device 18 is an annular chuck structure, including an outer ring 1801 and an inner ring 1802. The radial end face of the outer ring 1801 is fixedly connected to the end face of the furnace shell by bolts. The inner ring 1802 has eight claws 1803, which radially tighten and clamp the outer wall end of furnace tube 1. The axial sleeve of the outer ring 1801 is slidably fitted onto the outside of the inner ring 1802. Eight fixing plates 1804 are fixed in a ring on the outer side wall of the inner ring 1802. Each fixing plate 1804 is fixed with a V-shaped elastic metal sheet 1805 between it and the radial end face of the outer ring 1801. When furnace tube 1 is heated and undergoes thermal stress deformation, the traditional eight-claw chuck fixing method restricts both ends of furnace tube 1. The axial stress generated by furnace tube 1 can only act on the furnace wall of furnace tube 1, resulting in a reduction in the service life of furnace tube 1. Using the eight-claw thermal compensation fixing device 18 of this application, the two ends of furnace tube 1 are fixedly connected to the furnace shell. When furnace tube 1 is heated and undergoes thermal stress deformation, furnace tube 1 transmits the force to inner ring 1802, inner ring 1802 transmits the force to fixing plate 1804, fixing plate 1804 transmits the force to V-shaped elastic metal sheet 1805. V-shaped elastic metal sheet 1805 deforms under force, thereby reducing the stress on furnace tube 1 and improving the service life of furnace tube 1.
[0024] The rotary drive assembly includes a variable frequency speed control motor 3 and a synchronous transmission gear set. The body of the variable frequency speed control motor 3 is fixed to the frame. The output shaft of the variable frequency speed control motor 3 extends along the axis of the furnace tube 1 and is fixedly connected to the drive gear 4 of the synchronous transmission gear set. The drive gear 4 of the synchronous transmission gear set meshes with a gear ring 5 fixed to the outer surface of the furnace body shell. The gear ring 5 is an annular gear ring 5, which is fixed to the outer circumference of the furnace body shell by bolts and positioning pins. The variable frequency speed control motor 3 outputs rotational power, which is transmitted to the gear ring 5 through the synchronous transmission gear set. The gear ring 5 drives the furnace body shell to rotate around the axis of the furnace tube 1. The furnace body shell synchronously drives the furnace tube 1 to rotate through the eight-claw thermal compensation fixing device 18, thereby realizing the coaxial synchronous rotation of the furnace body assembly 2 and the furnace tube 1.
[0025] The support and positioning assembly includes a rolling ring 6 and support rollers 7. The rolling ring 6 is an annular ring, fixed to the outer circumference of the furnace shell by bolts and positioning pins. The axle of the support roller 7 is fixed to the frame by a bearing seat. The outer ring 1801 of the support roller 7 has a groove adapted to the rolling ring 6, and the outer circumference of the groove makes rolling contact with the outer circumference of the rolling ring 6. At least two sets of support rollers 7 are provided, located on both sides of the furnace shell along the axial direction. Each set of support rollers 7 includes two rollers, which are symmetrically distributed on both sides of the outer circumference of the rolling ring 6 along the circumference of the furnace shell, forming a V-shaped support. When the rolling ring 6 rotates with the furnace shell, it rolls on the wheel surface of the support rollers 7. The support rollers 7 bear the radial load of the furnace assembly 2 and the furnace tube 1, and at the same time constrain the axial position of the furnace assembly 2, so that the furnace assembly 2 rotates stably around the axis without axial displacement.
[0026] Flanges 8 are installed at both ends of the furnace tube 1. Flanges 8 are annular disc-shaped structures, detachably connected to the eight-claw thermal compensation fixing device 18 at the end of the furnace tube 1 via bolts. Flanges 8 rotate synchronously with the furnace tube 1. A circular through-hole is formed in the center of flange 8, penetrating the flange 8 and connecting the inner cavity of the furnace tube 1 to external piping. A PTFE filter cloth 9 is installed on the inner side of flange 8. The PTFE filter cloth 9 is a disc-shaped high-temperature resistant component that seals the inner surface of the circular through-hole of flange 8, reducing heat loss at the end of the furnace tube 1.
[0027] A diaphragm valve 10 and a rotary joint 11 are sequentially installed on the outer sides of the flanges 8 at both ends of the furnace tube 1. The rotary joint 11 consists of a stationary sealing seat and a dynamic sealing surface. The stationary sealing seat is fixed to the frame by a bracket, and the dynamic sealing surface is in contact with the outer end face of the flange 8 that rotates with the furnace tube 1. A rotary sealing pair is formed between the stationary sealing seat and the dynamic sealing surface, allowing the furnace tube 1 to rotate around its axis while maintaining a seal, preventing the inner cavity of the furnace tube 1 from communicating with the external atmosphere. It should be noted that since the furnace body assembly 2 rotates synchronously with the furnace tube 1, the rotary seal only needs to be installed between the flange 8 at the end of the furnace tube 1 and the stationary part of the frame. The sealing surface only bears the single relative rotation between the end of the furnace tube 1 and the stationary pipeline, and there is no need to set an additional sealing structure between the furnace body assembly 2 and the furnace tube 1.
[0028] In some embodiments, the rotary seal is a mechanical seal, in which a stationary ring is embedded in the stationary side sealing seat, and the dynamic sealing surface is a dynamic ring fixed to the outer end face of the flange 8. The end faces of the stationary ring and the dynamic ring fit together to form a sealing surface, and the sealing surfaces are kept in contact by spring preload.
[0029] The stationary side sealing seat of the rotary joint 11 is connected to the gas pipeline 12. The gas pipeline 12 at the gas inlet end of the furnace tube 1 is connected to a gas supply source, and the gas pipeline 12 at the gas outlet end of the furnace tube 1 is connected to the gas inlet of the vacuum pump 13. Gas enters the inner cavity of the furnace tube 1 through the rotary seal via the gas pipeline 12 at the gas inlet end, and is extracted by the vacuum pump 13 through the gas pipeline 12 at the gas outlet end, thereby establishing a negative pressure environment in the inner cavity of the furnace tube 1, promoting the desorption and discharge of impurity gases in the quartz sand.
[0030] A water-cooled inlet guide ring 14 and a water-cooled return guide ring 15 are also provided on the side wall of the furnace tube 1 at the gas outlet end. A water-cooled water guide pipe is also provided inside the side wall of the furnace tube 1, which is connected to the water-cooled inlet guide ring 14 and the water-cooled return guide ring 15. The coolant enters the water-cooled water guide pipe inside the furnace tube 1 through the water-cooled inlet guide ring 14, and then the coolant flows out from the water-cooled return guide ring 15, carrying away the heat on the surface of the furnace tube 1 and reducing the thermal stress deformation of the furnace tube 1.
[0031] Furthermore, to achieve automatic sliding discharge of the material after purification, one end of the frame near the air inlet of furnace tube 1 is hinged to the ground foundation via a hinge shaft 16, which extends along the width of furnace tube 1. A lifting push rod 17 is installed at the bottom of the other end of the frame. The fixed end of the lifting push rod 17 is hinged to the ground foundation, and the push rod component of the lifting push rod 17 extends and retracts vertically, with its top end hinged to the bottom of the frame. When the lifting push rod 17 extends, the top end of the push rod pushes the frame, causing the frame to tilt in the vertical plane around the hinge shaft 16. After the frame tilts, the axis of furnace tube 1 tilts relative to the horizontal plane, and the material inside the furnace tube 1 slides along the axis towards the discharge end under the influence of gravity, coordinating with the rotation of furnace tube 1 to achieve discharge.
[0032] In some embodiments, the lifting push rod 17 is an electric push rod with a built-in lead screw and nut pair. The motor drives the lead screw to rotate, causing the push rod to extend and retract in the vertical direction.
[0033] A method for purifying high-purity synthetic quartz sand: In use, firstly, the furnace tube 1 is fixed to both ends of the furnace shell by the eight-claw thermal compensation fixing device 18, so that the furnace tube 1 is coaxially inserted into the furnace body assembly 2. The toothed ring 5 and the rolling ring 6 are respectively fixed to the outer circumferential surface of the furnace shell by bolts and positioning pins. The furnace body assembly 2 is hoisted onto the support roller 7 of the frame, so that the rolling ring 6 and the wheel surface of the support roller 7 make rolling contact. The quartz sand material to be purified is fed into the quartz sand purification chamber from the feed end of the furnace tube 1. During the feeding process, the rotary drive component drives the furnace tube 1 to rotate in the opposite direction, and the material shovel at the feed end feeds the material into the inner cavity of the furnace tube 1. After the material is loaded, flange 8 and PTFE filter cloth 9 are installed at both ends of furnace tube 1. Flange 8 is connected and fastened to octagonal thermal compensation fixing device 18 by bolts. Then, diaphragm valve 10 and rotary joint 11 are installed in sequence so that the static side sealing seat of rotary joint 11 is in contact with the dynamic sealing surface of rotary joint 11 on the outer end face of flange 8 to achieve sealing. Gas pipeline 12 is connected to the static side sealing seat of rotary seal respectively. Start the variable frequency speed control motor 3. The output shaft of the variable frequency speed control motor 3 drives the gear ring 5 to rotate through the synchronous transmission gear set. The gear ring 5 drives the furnace shell to rotate. The furnace shell drives the furnace tube 1 to rotate synchronously through the eight-claw thermal compensation fixing device 18. The furnace body assembly 2 and the furnace tube 1 rotate around the same axis at the same speed. The heating element rotates with the furnace body assembly 2 and there is no relative rotation between it and the furnace tube 1. The heating element is started to heat up to the process temperature and maintain a constant temperature. During the heat preservation and purification stage, the furnace tube 1 rotates continuously. The quartz sand material in the inner cavity of the furnace tube 1 tumbles under the action of gravity. The material particles are alternately exposed to the heating radiation to achieve uniform heating. At the same time, the vacuum pump 13 is started to draw a vacuum in the inner cavity of the furnace tube 1 through the gas pipeline 12 at the gas outlet end, so that the quartz sand purification chamber is in a negative pressure state. The impurities in the quartz sand are vaporized and desorbed at high temperature. The negative pressure environment causes the impurity gas to be discharged from the discharge end along the airflow direction and extracted by the vacuum pump 13. During the heat preservation and purification stage, process gas is simultaneously introduced into the inner cavity of furnace tube 1 through gas pipeline 12 at the feed end. After the process gas flows along the axial direction across the material surface, it is extracted from the discharge end by vacuum pump 13, forming a directional airflow that carries impurity gas out. After purification, heating is stopped. Once the temperature inside the furnace tube 1 drops to the material collection temperature, the flange 8 and rotary seal at the discharge end are removed. The lifting push rod 17 is activated to tilt the frame, causing the axis of the furnace tube 1 to tilt relative to the horizontal plane. The rotary drive assembly drives the furnace tube 1 to rotate in the forward direction. Under the influence of gravity and rotation, the material slides along the axis towards the discharge end and is discharged, completing the material collection. After the material collection is completed, the lifting push rod 17 retracts to restore the frame to a horizontal state.
[0034] In this embodiment, the furnace body assembly 2 and the furnace tube 1 are rigidly connected as one unit by an octagonal thermal compensation fixing device 18, and are synchronously driven by the same rotary drive assembly via a gear ring 5. The furnace body assembly 2 and the furnace tube 1 rotate around the same axis at the same speed. Therefore, there is no relative movement between the heating element fixed to the inner wall of the insulation layer 201 and the furnace tube 1. The radiation distance and radiation angle of the heating element to each area of the outer wall of the furnace tube 1 remain constant. The amount of heat radiation received by each position around the circumference of the furnace tube 1 is consistent, eliminating the circumferential temperature fluctuations caused by the relative movement between the heating zone and the furnace tube 1. This makes the temperature field inside the furnace tube 1 uniform and stable, ensuring that the quartz sand material is heated uniformly throughout, and that impurities are fully vaporized and desorbed under a uniform temperature field.
[0035] Since there is no relative movement between the furnace body assembly 2 and the furnace tube 1, no relative friction occurs between the outer wall of the furnace tube 1 and the inner wall of the furnace body shell. This eliminates the wear and stress deformation of the furnace tube 1 wall caused by relative rotation, extending the service life of the furnace tube 1. Simultaneously, the eight-claw thermal compensation fixing device 18 of this invention not only rigidly connects the furnace tube 1 and the furnace body, but also absorbs the thermal stress on the furnace tube 1 through the deformation of the V-shaped elastic metal sheet 1805 when the furnace tube 1 undergoes axial thermal stress deformation due to heat, thereby protecting the furnace tube 1 and effectively preventing furnace explosion caused by thermal stress deformation of the furnace tube 1.
[0036] Since the furnace body assembly 2 and the furnace tube 1 rotate synchronously as a whole, there is no need to set a sealing structure between them. The rotary seal is only set between the end flange 8 of the furnace tube 1 and the stationary parts of the frame. The number of sealing pairs is reduced, and the sealing surface only bears a single relative rotation, which reduces the risk of seal failure and reduces heat loss due to air leakage.
[0037] Since the material is heated evenly by gravity during the rotation of the furnace tube 1, there is no need to set up a stirring structure inside the furnace tube 1, thus avoiding secondary pollution of the quartz sand material by the precipitation of metal impurities by the stirring components under high temperature environment.
[0038] The embodiments of the present invention have been described above. However, the embodiments are not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make more equivalent embodiments under the guidance of the present embodiments, and all of them are within the protection scope of the present embodiments.
Claims
1. A high-purity synthetic quartz sand purification device, characterized in that, include: frame; A furnace body assembly, wherein the furnace body assembly is a cylindrical shell structure, and a heating element for heating is fixed on the inner wall of the furnace body assembly; The furnace tube is coaxially inserted inside the furnace body assembly. The inner cavity of the furnace tube forms a quartz sand purification chamber. Both ends of the furnace tube are rigidly connected to the outer shell of the furnace body assembly through thermal compensation fixing devices. The thermal compensation fixing device is an eight-claw thermal compensation fixing device, which is a ring chuck structure, including an outer ring and an inner ring. The radial end face of the outer ring is fixedly connected to the end face of the furnace shell by bolts. The inner ring has eight claws. The eight claws radially tighten and clamp the end of the outer wall of the furnace tube. The axial sleeve of the outer ring is slidably sleeved on the outside of the inner ring. Eight fixing plates are fixed in a ring on the outer side wall of the inner ring. A V-shaped elastic metal sheet is fixed between each fixing plate and the radial end face of the outer ring. A rotary drive assembly is fixed to the frame and driven to the furnace shell, driving the furnace body assembly and the furnace tube to rotate synchronously around the same axis, so that there is no relative movement between the heating element and the furnace tube; A support and positioning assembly is disposed between the frame and the furnace shell to bear the radial load of the furnace assembly and the furnace tube and to constrain the axial position.
2. The high-purity synthetic quartz sand purification device according to claim 1, characterized in that, The outer layer of the furnace body assembly is the furnace shell. An insulation layer is attached and fixed to the inner wall of the furnace shell. The heating element is fixed to the inner wall of the insulation layer. The heating element is a resistance wire arranged along the axis of the furnace tube and surrounds the outer wall of the furnace tube. The heating element is connected to an external power source through a conductive slip ring. The rotating ring of the conductive slip ring is fixed to the furnace shell, and the stationary ring of the conductive slip ring is fixed to the frame. The rotating ring maintains sliding conductive contact with the stationary ring through a brush.
3. The high-purity synthetic quartz sand purification device according to claim 2, characterized in that, The rotary drive assembly includes a variable frequency speed control motor and a synchronous transmission gear set. The body of the variable frequency speed control motor is fixed to the frame. The output shaft of the variable frequency speed control motor is fixedly connected to the drive gear of the synchronous transmission gear set. The drive gear of the synchronous transmission gear set meshes with a gear ring fixed to the outer surface of the furnace shell. The gear ring is an annular gear ring and is fixed to the outer circumference of the furnace shell by bolts and positioning pins.
4. The high-purity synthetic quartz sand purification device according to claim 3, characterized in that, The support and positioning assembly includes a rolling ring and support rollers. The rolling ring is an annular ring body, which is fixed to the outer circumferential surface of the furnace shell by bolts and positioning pins. The axle of the support roller is fixed to the frame by a bearing seat. The outer ring of the support roller has a groove adapted to the rolling ring, and the outer circumferential surface of the groove makes rolling contact with the outer circumferential surface of the rolling ring. At least two sets of support rollers are provided, located on both sides of the furnace shell along the axial direction. Each set of support rollers includes two rollers, which are symmetrically distributed on both sides of the outer circumferential surface of the rolling ring along the circumference of the furnace shell, forming a V-shaped support.
5. The high-purity synthetic quartz sand purification device according to claim 4, characterized in that, Flanges are installed at both ends of the furnace tube. The flanges are annular disc-shaped structures and are detachably connected to the ends of the furnace tube by bolts and rotate synchronously with the furnace tube. A circular through hole is opened in the center of the flange, which passes through the flange and connects the inner cavity of the furnace tube with the external pipeline. A PTFE filter cloth is installed on the inner side of the flange and seals the inner side of the circular through hole of the flange.
6. The high-purity synthetic quartz sand purification device according to claim 5, characterized in that, A diaphragm valve and a rotary joint are sequentially installed on the outer side of the flanges at both ends of the furnace tube.
7. The high-purity synthetic quartz sand purification device according to claim 6, characterized in that, The stationary side sealing seat of the rotary joint is connected to the gas pipeline, the gas pipeline at the gas inlet end of the furnace tube is connected to the gas supply source, and the gas pipeline at the gas outlet end of the furnace tube is connected to the gas inlet of the vacuum pump.
8. The high-purity synthetic quartz sand purification device according to claim 7, characterized in that, The furnace tube sidewall at the gas outlet end is also provided with a water-cooled inlet guide ring and a water-cooled return guide ring, and a water-cooled water guide pipe is also provided inside the sidewall of the furnace tube, which is connected to the water-cooled inlet guide ring and the water-cooled return guide ring.
9. The high-purity synthetic quartz sand purification apparatus according to claim 8, characterized in that, One end of the frame near the gas inlet of the furnace tube is hinged to the ground foundation via a hinge shaft, which extends along the width of the furnace tube. A lifting push rod is provided at the bottom of the other end of the frame. The fixed end of the lifting push rod is hinged to the ground foundation, and the top end of the push rod is hinged to the bottom of the frame. When the lifting push rod extends, it pushes the frame, causing the frame to tilt in the vertical plane around the hinge shaft, resulting in an angle of inclination of the furnace tube's axis relative to the horizontal plane. Under the action of gravity, the material in the inner cavity of the furnace tube slides along the axial direction towards the discharge end.
10. A method for purifying high-purity synthetic quartz sand, using the high-purity synthetic quartz sand purification apparatus as described in claim 9, characterized in that, Includes the following steps: When in use, first fix the furnace tube to both ends of the furnace shell using the eight-claw thermal compensation fixing device, so that the furnace tube is coaxially inserted into the furnace body assembly. Fix the toothed ring and rolling ring to the outer circumference of the furnace shell using bolts and positioning pins. Hoist the furnace body assembly onto the support rollers of the frame, so that the rolling ring makes rolling contact with the wheel surface of the support rollers. The quartz sand material to be purified is fed into the quartz sand purification chamber from the feed end of the furnace tube. During the feeding process, the rotary drive component drives the furnace tube to rotate in the opposite direction, and the material shovel at the feed end feeds the material into the inner cavity of the furnace tube. After the material is loaded, the flange and PTFE filter cloth are installed at both ends of the furnace tube. The flange is then connected and fastened to the octagonal thermal compensation fixing device with bolts. Then, the diaphragm valve and rotary joint are installed in sequence, so that the static side sealing seat of the rotary joint is in contact with the dynamic sealing surface of the rotary joint on the outer end face of the flange to achieve a seal. The gas pipeline is then connected to the static side sealing seat of the rotary seal respectively. Start the variable frequency speed control motor. The output shaft of the variable frequency speed control motor drives the gear ring to rotate through the synchronous transmission gear set. The gear ring drives the furnace shell to rotate. The furnace shell drives the furnace tube to rotate synchronously through the eight-claw thermal compensation fixing device. The furnace body assembly and the furnace tube rotate around the same axis at the same speed. The heating element rotates with the furnace body assembly and there is no relative rotation between it and the furnace tube. The heating element is activated to raise the temperature to the process temperature and maintain it at a constant temperature. During the heat preservation and purification stage, the furnace tube rotates continuously. The quartz sand material in the inner cavity of the furnace tube tumbles under the action of gravity. The material particles are alternately exposed to the heating radiation to achieve uniform heating. At the same time, the vacuum pump is activated to evacuate the inner cavity of the furnace tube through the gas pipeline at the gas outlet, so that the quartz sand purification chamber is in a negative pressure state. The impurities in the quartz sand are vaporized and desorbed at high temperature. The negative pressure environment causes the impurity gas to be discharged from the discharge end along the airflow direction and then extracted by the vacuum pump. During the heat preservation and purification stage, process gas is simultaneously introduced into the inner cavity of the furnace tube through the gas pipeline at the feed end. The process gas flows along the axial direction across the surface of the material and is then extracted by the vacuum pump at the discharge end, forming a directional airflow that carries impurity gas out. After purification, heating is stopped. Once the temperature inside the furnace tube drops to the material collection temperature, the flange and rotary seal at the discharge end are removed. The lifting push rod is then activated to tilt the frame, creating an angle between the furnace tube axis and the horizontal plane. The rotary drive assembly drives the furnace tube to rotate in the forward direction. Under the influence of gravity and rotation, the material slides along the axis towards the discharge end and is discharged, completing the material collection process. After material collection is completed, the lifting push rod retracts to restore the frame to a horizontal state.