High-purity quartz sand anti-pollution constant-pressure sealing trolley and high-purity quartz sand transfer method

Abstract

A high-purity quartz sand anti-pollution constant-pressure sealing trolley comprises a hollow box body with the top open, a sealing cover is detachably installed on the top of the trolley box body to achieve sealing of the box body, an exhaust port is formed in the side portion of the box body, and an air inlet capable of filling inert gas into the box body is formed in the side, opposite to the exhaust port, of the box body. And the interior of the box body is kept at positive pressure. The invention further provides a high-purity quartz sand transferring method. Through inert gas positive pressure closed-loop control, the situation that the hydroxyl content of quartz sand exceeds the standard after external air permeates into the box body is prevented, effective control over metal pollution increment can be achieved, and the 5N-grade quartz sand can still meet the technological requirements for the cleanliness and the particle proportion of a large-size semiconductor crucible after being transferred.

Description

Technical Field

[0001] This invention relates to the field of quartz crucible production technology, and in particular to a high-purity quartz sand anti-contamination constant pressure sealed trolley and a high-purity quartz sand transfer method. Background Technology

[0002] Quartz crucibles are key components of photovoltaic single-crystal furnaces, serving as consumable containers for pulling large-diameter single-crystal silicon. They are primarily used to hold molten silicon and form the crystal rods needed for subsequent processes. The production principle of quartz crucibles is as follows: high-purity quartz sand is loaded into a rotating mold that can be tilted at any angle. Centrifugal force is used to shape the crucible. The rotating device, now in crucible shape, is moved to the electrode rod, where an arc is ignited by applying electricity. Simultaneously, a vacuum system is activated, rapidly melting the quartz into a crucible-shaped molten quartz. After cooling, the crucible is removed, completing the melting process for one quartz crucible. As the main raw material for quartz crucible production, each crucible, depending on its size and model, may consume tens or even hundreds of kilograms of high-purity quartz sand. With the rapid development of the semiconductor industry, the demand for quartz crucibles is also gradually increasing.

[0003] In the manufacturing process of semiconductor and photovoltaic grade quartz crucibles, there is a significant technical bottleneck in the transfer of high-purity quartz sand: when the current mainstream manual handling or ordinary sealed carts are used for transfer, the air with a certain degree of humidity from the outside can penetrate into the cart, which can easily cause the hydroxyl content of the quartz sand to exceed the standard, directly affecting the performance of the crucible when it is melted at high temperature. Summary of the Invention

[0004] In order to solve the technical problems existing in the above-mentioned technologies, it is necessary to provide a high-purity quartz sand anti-pollution constant pressure sealing trolley.

[0005] A high-purity quartz sand anti-pollution constant pressure sealing trolley includes a hollow box with an open top. The top of the box is detachably fitted with a sealing cover to achieve sealing of the box. An exhaust port is provided on the side of the box, and an air inlet is provided on the side of the box opposite to the exhaust port to allow inert gas to be injected into the box to maintain positive pressure inside the box.

[0006] Preferably, the inner wall of the enclosure is lined with quartz glass.

[0007] Preferably, the bottom of the box is provided with a shock-absorbing moving component to reduce vibration when the box moves. The shock-absorbing moving component includes a damping part and moving wheels; the upper end of the damping part is connected to the bottom of the box, and the lower end of the damping part is connected to the moving wheels.

[0008] Preferably, the shock-absorbing part includes an upper connecting plate, a lower connecting plate, a spring rod, and a limiting member; the upper connecting plate is fixed to the bottom of the housing, the lower connecting plate is located directly below the upper connecting plate, the lower connecting plate is used to install the moving wheel, the upper end of the spring rod is connected to the upper connecting plate, the lower end of the spring rod is connected to the lower connecting plate, and the limiting member is installed between the upper connecting plate and the lower connecting plate to limit the maximum distance between the upper connecting plate and the lower connecting plate.

[0009] Preferably, the limiting component includes an upper connecting pipe and a lower connecting pipe; the upper connecting pipe is fixed to the lower end of the upper connecting plate, and the lower end of the upper connecting pipe has a limiting block; the lower connecting pipe is fixed to the upper end of the lower connecting plate, and the upper end of the lower connecting pipe is slidably fitted outside the upper connecting pipe; the upper end of the lower connecting pipe has a limiting ring that can block the limiting block.

[0010] Preferably, an electrostatic protective layer is sprayed onto the outer wall of the enclosure.

[0011] Preferably, an electrostatic eliminator is installed inside the enclosure.

[0012] It is also necessary to provide a method for transporting high-purity quartz sand.

[0013] A method for transferring high-purity quartz sand, using the aforementioned high-purity quartz sand anti-pollution constant pressure sealed trolley, includes the following steps: Step S1: Pre-purify the container; Step S2: Fill the box with high-purity quartz sand; Step S3: Control the chamber to travel along the preset path in the cleanroom at a speed of 0.5m / s, and keep the vibration intensity of the chamber suppressed to 0.3g; Step S4: After the box arrives at the crucible casting platform, it is sealed and connected with the crucible melting equipment. The feeder feeds the material at a constant speed to complete the transfer of high-purity quartz sand.

[0014] Preferably, in step S1, the pre-purification treatment of the enclosure is carried out in the following manner: The control box moves to the outlet of the quartz sand purification furnace; Connect the air inlet to the furnace body vacuum valve via a telescopic conduit; Open the valve on the exhaust port and fill the chamber with nitrogen three times at a flow rate of 10L / min. After the air inside the chamber is purged, close the valve on the exhaust port while maintaining a positive pressure of 0.08±0.005MPa.

[0015] Preferably, in step S2, the high-purity quartz sand is loaded into the box in the following manner: Start the static eliminator before loading; High-purity quartz sand is loaded into the box at a flow rate of 0.15 m³ / s, and the static eliminator is kept working continuously to keep the surface potential of the sand particles ≤ 5V.

[0016] Compared with existing technologies, the high-purity quartz sand anti-contamination constant pressure sealed trolley and high-purity quartz sand transfer method provided by this invention address the purity and particle integrity protection requirements of quartz sand as the main raw material for quartz crucibles. The inner lining of the box is made of high-purity quartz glass / SiO2≥99.995%, which can prevent the precipitation of impurity ions such as Fe and Al after the metal box comes into contact with the quartz sand. The shock absorption system can prevent the generation of secondary powder by mechanical friction between particles caused by transportation vibration, reducing the raw material breakage rate. The use of an electrostatic eliminator can prevent the loss of raw materials due to electrostatic adsorption of quartz sand during flow. The positive pressure closed-loop control of inert gas can prevent the infiltration of external air into the box from causing the hydroxyl content of quartz sand to exceed the standard, and can effectively control the increase of metal contamination, so that the 5N grade quartz sand still meets the process requirements of cleanliness and particle ratio for large-size semiconductor crucibles after transfer. Attached Figure Description

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 This is a schematic diagram of the high-purity quartz sand anti-pollution constant pressure sealing trolley of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of the limiting component of the present invention.

[0020] In the diagram: Box body 01, Sealed cover 02, Exhaust port 03, Air inlet 04, Shock-absorbing moving assembly 05, Shock-absorbing part 51, Upper connecting plate 511, Lower connecting plate 512, Spring rod 513, Limiting component 514, Upper connecting pipe 5141, Lower connecting pipe 5142, Limiting block 5143, Limiting ring 5144, Moving wheel 52. Detailed Implementation

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] In the description of this invention, it should be understood that the terms "upper", "middle", "outer", "inner", "lower", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0023] Please refer to Figure 1 In one embodiment, the present invention provides a high-purity quartz sand anti-pollution constant pressure sealing trolley, including a hollow box 01 with an open top. A detachable sealing cover 02 is installed on the top of the box 01 to achieve sealing. The sealing cover 02 can be sealed by an actuation method, with a closing pressure ≥5KN. The contact surface between the sealing cover 02 and the upper end of the box 01 uses a fluororubber sealing ring, which can withstand a high temperature of 250℃ to improve the sealing effect. An exhaust port 03 is provided on the side of the box 01, and an air inlet 04 is provided on the side of the box 01 opposite to the exhaust port 03 to allow inert gas to be introduced into the box 01, maintaining a positive pressure inside the box 01. Nitrogen or argon can be used as the inert gas. By using inert gas positive pressure closed-loop control, external air is prevented from penetrating into the chamber 01, which would cause the hydroxyl content of the quartz sand to exceed the standard. This prevents air from contacting the quartz sand and reduces the risk of pollution such as oxidation. Furthermore, it can effectively control the increase in metal pollution, ensuring that the 5N grade quartz sand still meets the process requirements for cleanliness and particle ratio of large-size semiconductor crucibles after transfer.

[0024] Of course, a pressure sensor is also installed on the chamber 01 to facilitate monitoring of the pressure.

[0025] In one embodiment, a quartz glass liner is provided on the inner wall of the housing 01. The liner material can be a high-purity quartz glass liner (SiO2≥99.995%) to prevent quartz sand from contacting the metal inner wall and reduce metal element contamination caused by physical contact.

[0026] In one embodiment, a shock-absorbing moving assembly 05 is provided at the bottom of the housing 01 to reduce vibration during movement of the housing 01. The shock-absorbing moving assembly 05 includes a damping part 51 and moving wheels 52; the upper end of the damping part 51 is connected to the bottom of the housing 01, and the lower end of the damping part 51 is connected to the moving wheels 52. The damping part 51 can reduce vibration during the transportation process of the trolley, thereby reducing particle loss of quartz sand caused by vibration.

[0027] Specifically, the shock-absorbing part 51 includes an upper connecting plate 511, a lower connecting plate 512, a spring rod 513, and a limiting member 514. The upper connecting plate 511 is fixed to the bottom of the housing 01, and the lower connecting plate 512 is located directly below the upper connecting plate 511. The lower connecting plate 512 is used to install the moving wheel 52. The upper end of the spring rod 513 is connected to the upper connecting plate 511, and the lower end of the spring rod 513 is connected to the lower connecting plate 512. The limiting member 514 is installed between the upper connecting plate 511 and the lower connecting plate 512 to limit the maximum distance between the upper connecting plate 511 and the lower connecting plate 512. When the spring rod 513 rebounds due to a bump, the limiting member 514 can limit the maximum upward rebound length of the spring rod 513, thereby limiting the upward movement distance of the upper connecting plate 511, so as to control the amplitude of the bump in the box 01, ensure that the box 01 can move more smoothly, and reduce the probability of the quartz sand in the box 01 flowing and rubbing due to the bump.

[0028] Please refer to Figure 2 Specifically, the limiting member 514 includes an upper connecting pipe 5141 and a lower connecting pipe 5142. The upper connecting pipe 5141 is fixed to the lower end of the upper connecting plate 511, and the lower end of the upper connecting pipe 5141 has a limiting block 5143. The lower connecting pipe 5142 is fixed to the upper end of the lower connecting plate 512, and the upper end of the lower connecting pipe 5142 is slidably fitted onto the outside of the upper connecting pipe 5141. The upper end of the lower connecting pipe 5142 has a limiting ring 5144 that can block the limiting block 5143. The inner hole of the limiting ring 5144 allows the upper connecting pipe 5141 to pass through, and the inner hole contacts the outer wall of the upper connecting pipe 5141, allowing the upper connecting pipe 5141 to slide up and down along the limiting ring 5144. The limiting hole slides up and down inside the lower connecting pipe 5142, thereby limiting the limiting block 5143 with the limiting ring 5144.

[0029] Of course, the limiting component 514 can also be made of silicone, which can serve as a limiting component and also as a shock absorber.

[0030] In one embodiment, an electrostatic protective layer is sprayed onto the outer wall of the housing 01.

[0031] In one embodiment, an electrostatic eliminator is installed inside the housing 01.

[0032] In one embodiment, the present invention provides a method for transporting high-purity quartz sand, using a high-purity quartz sand anti-contamination constant pressure sealed trolley for transport, comprising the following steps: Step S1: Pre-purify the housing 01; Step S2: Fill the box 01 with high-purity quartz sand; Step S3: Control the box 01 to travel along the preset path of the clean room at a speed of 0.5m / s, and keep the vibration intensity of the box 01 suppressed to 0.3g; Step S4: After the box 01 arrives at the crucible casting platform, it is sealed and connected with the crucible melting equipment. The feeder feeds the material at a constant speed to complete the transfer of high-purity quartz sand.

[0033] To elaborate in detail, in step S1, the pre-purification treatment of box 01 adopts the following method: Control box 01 moves to the outlet of the quartz sand purification furnace; Connect the air inlet 04 to the furnace body vacuum valve via a telescopic conduit; Open the valve on the exhaust port 03 and purge the chamber 01 with nitrogen three times at a flow rate of 10L / min. After the air inside the chamber 01 is purged, close the valve on the exhaust port 03 and maintain a positive pressure of 0.08±0.005MPa.

[0034] To elaborate in detail, in step S2, the high-purity quartz sand is loaded into the housing 01 in the following manner: Start the static eliminator before loading; High-purity quartz sand is loaded into box 01 at a flow rate of 0.15 m³ / s, and the static eliminator is kept working continuously to keep the surface potential of the sand particles ≤ 5V.

[0035] During loading, the sealed cover can be opened for loading, or a separate feed pipe can be installed for loading. Of course, a valve is installed on the feed pipe.

[0036] Verification results from the testing of quartz sand before and after transport by the trolley show that: Increase in metal pollution: 0.7 ppb (ICP-MS method, main elements Fe / Al / K), an 80% reduction compared to the original vehicle; Particle breakage rate: 0.028% (D50 value compared with laser particle size analyzer), breakage rate reduced by 65%; Static electricity loss: 0.005 kg / ton (weighing method), loss rate reduced by 40%.

[0037] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the invention. Those skilled in the art will understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A high-purity quartz sand anti-pollution constant pressure sealing trolley, characterized in that: The vehicle includes a hollow, open-top box with a removable, airtight cover on the top to seal the box. An exhaust port is provided on the side of the box, and an air inlet is provided on the side of the box opposite to the exhaust port to allow inert gas to be introduced into the box to maintain positive pressure inside the box.

2. The high-purity quartz sand anti-pollution constant pressure sealing trolley according to claim 1, characterized in that: The inner wall of the enclosure is lined with quartz glass.

3. The high-purity quartz sand anti-pollution constant pressure sealing trolley according to claim 2, characterized in that: The bottom of the box is equipped with a shock-absorbing moving component to reduce vibration when the box moves. The shock-absorbing moving component includes a damping part and moving wheels; the upper end of the damping part is connected to the bottom of the box, and the lower end of the damping part is connected to the moving wheels.

4. The high-purity quartz sand anti-pollution constant pressure sealing trolley according to claim 3, characterized in that: The shock-absorbing part includes an upper connecting plate, a lower connecting plate, a spring rod, and a limiting member; the upper connecting plate is fixed to the bottom of the housing, the lower connecting plate is located directly below the upper connecting plate, the lower connecting plate is used to install the moving wheels, the upper end of the spring rod is connected to the upper connecting plate, the lower end of the spring rod is connected to the lower connecting plate, and the limiting member is installed between the upper connecting plate and the lower connecting plate to limit the maximum distance between the upper connecting plate and the lower connecting plate.

5. The high-purity quartz sand anti-pollution constant pressure sealing trolley according to claim 4, characterized in that: The limiting component includes an upper connecting pipe and a lower connecting pipe; the upper connecting pipe is fixed to the lower end of the upper connecting plate, and the lower end of the upper connecting pipe has a limiting block; the lower connecting pipe is fixed to the upper end of the lower connecting plate, and the upper end of the lower connecting pipe is slidably fitted outside the upper connecting pipe; the upper end of the lower connecting pipe has a limiting ring that can block the limiting block.

6. The high-purity quartz sand anti-pollution constant pressure sealing trolley according to claim 3, characterized in that: An electrostatic protective layer is sprayed onto the outer wall of the enclosure.

7. The high-purity quartz sand anti-pollution constant pressure sealing trolley according to claim 6, characterized in that: An electrostatic eliminator is installed inside the enclosure.

8. A method for transporting high-purity quartz sand, comprising using a high-purity quartz sand anti-pollution constant pressure sealed trolley as described in any one of claims 1-7 for transport, characterized in that: Includes the following steps, Step S1: Pre-purify the container; Step S2: Fill the box with high-purity quartz sand; Step S3: Control the chamber to travel along the preset path in the cleanroom at a speed of 0.5m / s, and keep the vibration intensity of the chamber suppressed to 0.3g; Step S4: After the box arrives at the crucible casting platform, it is sealed and connected with the crucible melting equipment. The feeder feeds the material at a constant speed to complete the transfer of high-purity quartz sand.

9. The method for transporting high-purity quartz sand according to claim 8, characterized in that: In step S1, the pre-purification treatment of the enclosure is carried out in the following manner: The control box moves to the outlet of the quartz sand purification furnace; Connect the air inlet to the furnace body vacuum valve via a telescopic conduit; Open the valve on the exhaust port and fill the chamber with nitrogen three times at a flow rate of 10L / min. After the air inside the chamber is purged, close the valve on the exhaust port while maintaining a positive pressure of 0.08±0.005MPa.

10. The method for transporting high-purity quartz sand according to claim 9, characterized in that: In step S2, the high-purity quartz sand is loaded into the box in the following manner. Start the static eliminator before loading; High-purity quartz sand is loaded into the box at a flow rate of 0.15 m³ / s, and the static eliminator is kept working continuously to keep the surface potential of the sand particles ≤ 5V.

Images