A method and device for preparing large-sized, gas-fused quartz glass ingot with few bubbles

Abstract

The present invention relates to a method and apparatus for preparing large-sized, low-bubble gas-melted quartz glass ingots, belonging to the technical field of quartz glass production. In the present invention, quartz sand raw materials are simultaneously fed by multiple oxyhydrogen burners. The oxyhydrogen flame ejected from the oxygen connecting pipe of the oxyhydrogen burner 4 melts into quartz glass liquid in a crucible. The simultaneous feeding of the multiple oxyhydrogen burners ensures the high temperature of the glass liquid in the crucible, further removes microbubbles and flocs in the glass liquid, and increases the feeding volume, thereby improving production efficiency. The crucible can help quartz glass liquid at a higher temperature condense and form, allowing the glass liquid in the crucible to be formed in one step, saving the existing thermal modification process and reducing the production cycle and cost. This solves the problem of impurity defects such as gas-liquid inclusions in the existing quartz sand structure, which causes the melted quartz glass to contain a large number of microbubbles and flocs, greatly reducing the quality of the quartz glass product.

Description

Technical Field

[0001] The invention relates to a method and a device for preparing a large-sized gas-fused quartz glass ingot with few bubbles, belonging to the technical field of quartz glass production. Background Art

[0002] Gas-fused quartz glass is primarily produced from natural quartz sand, which is melted in a melting furnace using an oxyhydrogen flame and then condensed. Because natural quartz sand is derived from crushed minerals, its structure contains impurities and defects such as gas-liquid inclusions. Consequently, the quartz glass produced from this raw material often contains numerous microbubbles and flocculent particles, significantly reducing the quality of the resulting quartz glass. Furthermore, the diameter of quartz glass produced by conventional gas-fused methods generally does not exceed 550 mm. To produce gas-fused quartz glass products with meter-scale diameters, it must be thermally modified using large electric heating furnaces. Therefore, there is a need to develop a preparation method and production apparatus that can effectively reduce microbubble defects within gas-fused quartz glass and enable the single-shot molding of large-scale quartz glass products. Summary of the Invention

[0003] The object of the present invention is to provide a method and apparatus for preparing a large-sized gas-fused quartz glass ingot with few bubbles, which can effectively reduce microbubble defects inside gas-fused quartz glass products and enable one-step molding of large-sized quartz glass products.

[0004] The technical solution of the present invention is:

[0005] A method for preparing a large-sized, gas-fused quartz glass ingot with few bubbles, characterized in that it comprises the following steps:

[0006] 1) First, install the crucible of the preparation device on the base rod through the base, then raise the base rod and extend it into the furnace of the melting furnace, so that there is a distance of 20-30 cm between the crucible and the burner on the top of the furnace to ensure that the glass liquid formed by the melting of the quartz sand is deposited in the crucible; then turn on the hydrogen and oxygen sources and start ignition under the conditions of (hydrogen 60L / min, oxygen 30L / min) to preheat the furnace and crucible;

[0007] 2) The burner is ignited and when the furnace temperature rises to 1200 degrees, the raw material bin is opened to allow the quartz sand in the raw material bin to enter the burner through the discharge pipe;

[0008] 3) During this process, the quartz sand raw material diffuses radially in the inner cavity of the shell (the cavity between the shell and the oxygen chamber B) under the action of the diffusion head at the port of the feed pipe; when the diffused quartz sand raw material merges with the hydrogen entering from the hydrogen inlet pipe, the hydrogen turns into a carrier for the quartz sand raw material, carrying the quartz sand raw material to continue downward, and mixes with the oxygen ejected from the oxygen connecting pipe to burn at the lower port of the burner, causing the quartz sand raw material to melt in the hydrogen-oxygen flame;

[0009] 4) During the melting of the quartz sand raw material in the hydrogen-oxygen flame, the lower end of each oxygen connecting pipe is inclined inward with the center point of the blocking plate as the base point; and the bottom of the burner shell is conical. The process of hydrogen and oxygen mixing and burning at the lower port of the burner is also a process of focusing hydrogen, oxygen and quartz sand raw material. At the same time, the ejected hydrogen forms a wind curtain around the oxygen ejected from the connecting pipe, which can make the gas-liquid inclusions contained in the natural quartz sand fully volatilized by the thermal reaction in flight and will not enter the glass liquid;

[0010] 5) The slurry formed after the quartz sand raw material is melted flows and gathers in the crucible; the slurry level in the crucible continues to rise. At this time, the base rod drives the crucible to descend as a whole (descending speed 5-8 mm / h), so that while the slurry level rises, the distance between the slurry level and the burner is always maintained within the range of (distance between 20-30 cm). The slurry formed after the raw material is melted flows and gathers in the crucible, and condenses in the crucible to form large-sized quartz glass products.

[0011] The preparation apparatus described in step 1) includes a melting furnace and a base rod extending into the melting furnace for lifting and lowering. A crucible is mounted on the top of the base rod extending into the melting furnace via a base. Multiple oxyhydrogen burners are installed at intervals on the top of the melting furnace corresponding to the crucibles. The lamp bodies of the oxyhydrogen burners are connected to the oxyhydrogen source and the raw material bin. The lamp mouths of the oxyhydrogen burners extend into the furnace of the melting furnace to melt the silicon dioxide raw material into a slurry liquid and collect it in the crucible to produce a quartz glass product.

[0012] The beneficial effects of the present invention are:

[0013] In the quartz glass production process, the present invention simultaneously feeds quartz sand raw material through multiple burners and melts it into quartz glass liquid in a large crucible under a hydrogen-oxygen flame. This allows the gas-liquid inclusions contained in the natural quartz sand to be fully volatilized by thermal reactions during operation and prevent them from entering the molten glass. The simultaneous feeding of the multiple burners not only maintains the high temperature of the molten glass in the crucible, further removing microbubbles and flocs, but also increases the feed volume and improves production efficiency. The large crucible facilitates condensation and molding of the quartz glass liquid at higher temperatures, and produces large-diameter quartz glass material in a single step, eliminating the existing thermal modification process and reducing production cycle and costs. The invention also solves the problem of impurity defects such as gas-liquid inclusions in the existing quartz sand structure, which results in the fused quartz glass containing a large number of microbubbles and flocs, significantly reducing the quality of the quartz glass product. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the structure of the oxyhydrogen burner of the present invention;

[0015] Figure 2 This is a schematic diagram of the working state of the hydrogen-oxygen burner of the present invention.

[0016] In the figure: 1. Shell 2. Blocking plate 3. Diffuser head 4. Feeding pipe 5. Oxygen connecting pipe 6. Hydrogen inlet pipe 7. Oxygen inlet pipe 8. Oxygen chamber A 9. Oxygen chamber B. DETAILED DESCRIPTION

[0017] The method for preparing a large-sized, gas-fused quartz glass ingot with few bubbles comprises the following steps:

[0018] First, the crucible of the preparation device is mounted on a base rod via a base. The preparation device includes a melting furnace and a base rod extending into the furnace chamber, which can be raised and lowered. The crucible is mounted on the top of the base rod through the base. The base includes a bottom plate and a base body. The bottom of the base body is provided with a stepped bottom plate, and the base body is fixedly connected to the base rod via the bottom plate. During operation, the base rises and falls or rotates with the base rod 2, and the crucible is movably mounted on the base body. Multiple hydrogen-oxygen burners are installed at intervals on the top of the furnace chamber corresponding to the crucible. These burners are connected to the hydrogen-oxygen gas source and the raw material storage bin. The lamp ends of the hydrogen-oxygen burners extend into the furnace chamber to melt the silica raw material into a slurry, which is then collected in the crucible to produce the quartz glass product.

[0019] The melting furnace includes a furnace body and a furnace chamber; the furnace body is cylindrical, and a furnace chamber is arranged inside the furnace body; the outer surface of the furnace body is provided with a thermal insulation layer; the inner surface of the furnace body is provided with a refractory layer, and flues are provided on the furnace body on both sides of the furnace chamber, one end of the flue is connected to the furnace chamber; the other end of the flue is connected to the outside of the furnace body; to discharge exhaust gas and quartz sand particles that have not been deposited on the material surface.

[0020] The oxyhydrogen burner consists of a housing 1, a feed pipe 4, an oxygen connecting pipe 5, and hydrogen and oxygen inlet pipes 6 and 7. The housing 1 is a conical structure with an open bottom. An oxygen chamber A8 is located in the center of the housing 1. An oxygen chamber B9 is located in a ring-shaped enclosure surrounding the oxygen chamber A8. Oxygen chambers A8 and B9 are sealed and independent of each other. A feed pipe 4 is located in the center of oxygen chamber A8, one end of which is connected to the feed silo. The other end of the feed pipe 4 extends into the housing 1. A diffuser head 3 is installed at the end of the feed pipe 4, which extends into the housing 1. This diffuser head 3 is a conical structure with a small top and a large bottom.

[0021] The bottom ports of oxygen chambers A8 and B9 are horizontally provided with baffles 2. Multiple oxygen connecting tubes 5 are regularly arranged on the lower surface of baffles 2. Through holes are provided in the corresponding baffles 2, and each oxygen connecting tube 5 communicates with the corresponding oxygen chamber A8 or oxygen chamber B9 through the through holes. The lower ends of each oxygen connecting tube 5 are aligned. A hydrogen inlet pipe 6 is provided on the shell 1. One end of this hydrogen inlet pipe 6 is connected to the hydrogen source, and the other end is connected to the cavity between the shell 1 and oxygen chamber B9. Oxygen inlet pipes 7 are respectively provided on oxygen chambers A8 and B9. One end of this oxygen inlet pipe 7 communicates with oxygen chambers A8 and B9, respectively, and the other end passes through the shell 1 to connect to the oxygen source. The lower ends of the oxygen connecting tubes 5 of the oxyhydrogen burner are arranged in a converging, inclined manner, with the center point of baffle 2 as the base point. The focal length of the hydrogen and oxygen mixture is thereby extended during operation; the lower ports of the oxygen connecting pipes 5 and the lower port of the housing 13 are arranged at different heights; so that the ejected hydrogen forms a wind curtain around the ejected oxygen.

[0022] Raise the base rod and extend it into the furnace of the melting furnace, keeping a distance of 20-30 cm between the crucible and the burner at the top of the furnace to ensure that the glass liquid formed by the melting of the quartz sand is deposited in the crucible; then turn on the hydrogen and oxygen sources and start ignition at 60 L / min of hydrogen and 30 L / min of oxygen to preheat the furnace and crucible;

[0023] The burner ignites and burns, and when the furnace temperature rises to 1200 degrees, the raw material bin is opened, allowing the quartz sand raw material in the raw material bin to enter the burner through the discharge pipe. During this process, the quartz sand raw material is diffused radially in the shell cavity (the cavity between the shell 1 and the oxygen chamber B9) under the action of the diffusion head at the discharge pipe port; when the diffused quartz sand raw material merges with the hydrogen entering from the hydrogen inlet pipe 6, the hydrogen is simultaneously converted into a carrier for the quartz sand raw material, carrying the quartz sand raw material to continue downward, and mixed with the oxygen ejected from the oxygen connecting pipe 5 at the lower port of the burner to burn, causing the quartz sand raw material to melt in the hydrogen-oxygen flame at 1700-1800 degrees. During the melting of the quartz sand in the hydrogen-oxygen flame, the lower ends of the oxygen connecting tubes 5 are arranged in an inwardly converging, angled configuration with the center of the baffle 2 as the base point. Furthermore, the bottom of the burner housing 1 is tapered, and the hydrogen and oxygen mix and burn at the burner's lower port, simultaneously focusing the hydrogen, oxygen, and quartz sand. Simultaneously, the ejected hydrogen forms a wind curtain around the oxygen ejected from the oxygen connecting tubes 5, allowing the gas-liquid inclusions in the natural quartz sand to be fully volatilized by the thermal reaction during flight and prevented from entering the molten glass. The molten slurry formed by the melting of the quartz sand flows and converges within the crucible. The slurry level within the crucible continues to rise. At this point, the base rod drives the crucible downward (at a rate of 5-8 mm / h), allowing the slurry level to rise while maintaining a constant distance between the slurry level and the burner within a range of 20-30 cm. The molten slurry flows and converges within the crucible, where it condenses to form a large-sized quartz glass product, completing the production of the quartz glass (ingot) product. In the present invention, quartz sand raw material is fed simultaneously by multiple oxyhydrogen burners. The oxyhydrogen flame ejected from the oxygen connecting pipe 5 of the oxyhydrogen burner 4 melts into quartz glass liquid in the crucible 3. The hydrogen gas ejected from the cavity between the shell 1 and the oxygen chamber B9 forms a protective layer (wind curtain) around the oxygen ejected from the oxygen connecting pipe 5, thereby increasing the length of the ejected flame, achieving the expansion of the high-temperature area, and increasing the time for the quartz sand to fly and melt. The gas-liquid inclusions contained in the natural quartz sand are fully volatilized by the thermal reaction during flight and will not enter the glass liquid. On the other hand, the simultaneous feeding of multiple oxyhydrogen burners not only ensures the high temperature of the glass liquid in the crucible, further removes microbubbles and flocs in the glass liquid, but also increases the feeding amount, thereby improving production efficiency. The crucible can help the quartz glass liquid at a higher temperature to condense and form, so that the glass liquid in the crucible is formed in one step, saving the existing thermal modification process and reducing the production cycle and cost. The invention solves the problem that impurity defects such as gas-liquid inclusions exist in the existing quartz sand structure, which causes the melted quartz glass to contain a large number of micro bubbles and flocs, greatly reducing the quality of the quartz glass product.

Claims

1. A method for preparing a large-sized, gas-fused quartz glass ingot with few bubbles, characterized in that: It includes the following steps: 1) First, install the crucible of the preparation device on the base rod through the base, then raise the base rod and extend it into the furnace of the melting furnace, so that the distance between the crucible and the hydrogen-oxygen burner on the top of the furnace is maintained at 20-30 cm to ensure that the glass liquid formed by the melting of the quartz sand is deposited in the crucible; then turn on the hydrogen and oxygen sources and start ignition under the conditions of hydrogen 60L / min and oxygen 30L / min to preheat the furnace and crucible; 2) The oxyhydrogen burner is ignited and when the furnace temperature rises to 1200°C, the raw material bin is opened, and the quartz sand in the raw material bin enters the oxyhydrogen burner through the feed pipe (4); 3) During this process, the quartz sand raw material diffuses radially in the cavity between the shell (1) and the oxygen chamber B (9) under the action of the diffusion head (3) at the end of the feed pipe (4); when the diffused quartz sand raw material merges with the hydrogen entering from the hydrogen inlet pipe (6), the hydrogen is simultaneously converted into a carrier of the quartz sand raw material, carrying the quartz sand raw material to continue downward, and mixed with the oxygen ejected from the oxygen connecting pipe (7) at the lower end of the hydrogen-oxygen burner to burn, so that the quartz sand raw material is melted in the hydrogen-oxygen flame; 4) During the melting process of the quartz sand raw material in the hydrogen-oxygen flame, since the lower end of each oxygen connecting pipe (7) is inclined at 45 degrees inwardly contracted with the center point of the blocking plate as the base point; and the bottom of the hydrogen-oxygen burner shell (1) is conical, the process of hydrogen and oxygen mixed and burned at the lower port of the hydrogen-oxygen burner is also a process of focusing hydrogen, oxygen and quartz sand raw materials, thereby extending the focal length. At the same time, the ejected hydrogen forms a wind curtain around the oxygen ejected from the connecting pipe, which can make the gas-liquid inclusions contained in the natural quartz sand fully volatilized by the thermal reaction in flight and will not enter the glass liquid; 5) When the slurry formed by the melting of the quartz sand raw material flows and gathers in the crucible, the slurry level in the crucible continues to rise. At this time, the base rod drives the crucible to descend as a whole, so that the slurry level rises while the distance between the slurry level and the hydrogen-oxygen burner is always kept within the range of 20-30 cm. 6) The slurry formed after the raw materials are melted flows and gathers in the crucible, and condenses in the crucible to form large-sized quartz glass products.

2. The method for preparing a large-sized, gas-fused quartz glass ingot with few bubbles according to claim 1, characterized in that: The preparation apparatus described in step 1) includes a melting furnace and a base rod extending into the melting furnace and capable of being raised and lowered. The apparatus is characterized in that a crucible is mounted on the top of the base rod extending into the melting furnace via a base. Multiple oxyhydrogen burners are installed at intervals on the top of the melting furnace corresponding to the crucibles. One end of the oxyhydrogen burner is connected to a hydrogen and oxygen source and a raw material bin, and the other end of the oxyhydrogen burner extends into the furnace of the melting furnace to melt the silicon dioxide raw material into a slurry, which is then collected in the crucible to produce a quartz glass product.

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