Method and apparatus for manufacturing glass substrates

Abstract

The present invention provides a method and apparatus for manufacturing a glass substrate that can reduce the concentration of corrosive gases in a pre-cabinet. [Solution] The main chamber 2 contains a furnace tube 21 in which a glass base material G is manufactured while a deposit of glass microparticles is contained inside. The furnace tube 21 is equipped with a manufacturing process in which a corrosive gas is introduced while the deposit of glass microparticles inside the furnace tube is sintered to manufacture the glass base material G. After the manufacturing process, a gas introduction process is performed in which the gas is introduced into a spare chamber 3. After the manufacturing process, a gas discharge process is performed in which the gas is discharged from at least one of the spare chamber 3 and the main chamber 2. The gas introduction process is started before the end of the gas discharge process.

Description

Technical Field

[0001] The present disclosure relates to a method and an apparatus for manufacturing a glass preform.

Background Art

[0002] Patent Document 1 discloses introducing a corrosive gas such as fluorine gas into the inside of a core tube in the manufacturing process of a glass preform.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an apparatus for manufacturing a glass preform, a core tube capable of accommodating a glass preform and a glass microparticle deposit for manufacturing the glass preform is accommodated inside. A preliminary chamber for accommodating the glass microparticle deposit and the manufactured glass preform is provided separately from the main chamber where the glass preform is manufactured. Since workers enter and exit the preliminary chamber for work, it is desirable to reduce the concentration of the corrosive gas in the preliminary chamber.

[0005] An object of the present disclosure is to provide a method and an apparatus for manufacturing a glass preform capable of reducing the concentration of a corrosive gas in a preliminary chamber.

Means for Solving the Problems

[0006] A method for manufacturing a glass base material according to one aspect of the present disclosure is a manufacturing apparatus comprising: a main chamber capable of manufacturing a glass base material while containing a deposit of glass microparticles inside; and a spare chamber communicating with the main chamber and formed to allow the deposit of glass microparticles and the glass base material to be inserted into and removed from the apparatus, wherein the method for manufacturing the glass base material comprises: a manufacturing step in which a furnace tube for manufacturing the glass base material while containing the deposit of glass microparticles inside is housed inside the main chamber, and a corrosive gas is introduced into the furnace tube while sintering the deposit of glass microparticles inside the furnace tube to manufacture the glass base material; a gas introduction step in which gas is introduced into the spare chamber after the manufacturing step; and a gas discharge step in which gas is discharged from at least one of the spare chamber and the main chamber after the manufacturing step, wherein the gas introduction step is started before the end of the gas discharge step.

[0007] A glass base material manufacturing apparatus according to one aspect of the present disclosure comprises: a main chamber capable of manufacturing a glass base material with a glass microparticle deposit contained inside; a spare chamber communicating with the main chamber and formed to allow the insertion and removal of the glass microparticle deposit and the glass base material; and a furnace tube housed inside the main chamber, which manufactures the glass base material with the glass microparticle deposit contained inside, wherein the furnace tube has a corrosive gas inlet for introducing corrosive gas during the sintering of the glass microparticle deposit; a gas inlet for introducing inert gas after the glass base material is manufactured is formed in either the main chamber or the spare chamber; and a gas outlet for discharging gas after the glass base material is manufactured is formed in the spare chamber. [Effects of the Invention]

[0008] According to this disclosure, a method and apparatus for manufacturing a glass matrix can be provided that can reduce the concentration of corrosive gases in a pre-cabinet. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 illustrates the manufacturing apparatus for glass base materials according to the first and second embodiments. [Figure 2] Figure 2 illustrates a manufacturing apparatus for a glass base material according to the third embodiment. [Figure 3] Figure 3 illustrates a manufacturing apparatus for a glass base material according to the fourth embodiment. [Modes for carrying out the invention]

[0010] (Description of the embodiments of this disclosure) First, embodiments of the present disclosure will be listed and described. (1) A method for manufacturing a glass base material according to one aspect of the present disclosure is a manufacturing apparatus comprising: a main chamber capable of manufacturing a glass base material with a glass microparticle deposit contained therein; and a spare chamber communicating with the main chamber and formed to allow the glass microparticle deposit and the glass base material to be inserted into and removed, wherein the method for manufacturing the glass base material comprises: a furnace tube for manufacturing the glass base material with the glass microparticle deposit contained therein contained within the main chamber, a manufacturing step of manufacturing the glass base material by sintering the glass microparticle deposit in the furnace tube while introducing a corrosive gas into the furnace tube; a gas introduction step of introducing gas into the spare chamber after the manufacturing step; and a gas discharge step of discharging gas from at least one of the spare chamber and the main chamber after the manufacturing step, wherein the gas introduction step is started before the end of the gas discharge step.

[0011] According to the glass base material manufacturing method described above, after the manufacturing process, a gas introduction process is performed to introduce gas into a spare chamber, and a gas discharge process is performed to discharge gas from at least one of the spare chamber and the main chamber. Therefore, even if corrosive gas introduced into the core tube during the manufacturing of the glass base material leaks out into the main chamber outside the core tube, the gas introduced into the spare chamber is discharged along with the corrosive gas, thereby reducing the concentration of corrosive gas in the spare chamber.

[0012] (2) In the method for manufacturing the glass base material according to (1) above, the gas discharge step may be a step of discharging gas from the pre-chamber.

[0013] According to the above method for manufacturing the glass base material, gas is discharged from the pre-chamber, making it less likely for corrosive gases to remain in the pre-chamber where the concentration of corrosive gases is to be reduced.

[0014] (3) In the method for manufacturing the glass base material according to (2) above, the gas introduction step and the gas discharge step may be performed alternately at least once each.

[0015] According to the above method for manufacturing the glass base material, the gas introduction process and the gas discharge process are performed alternately at least once each. Since no gas is introduced during the gas discharge process, complex control of the gas introduction and gas discharge processes becomes unnecessary. Furthermore, the degree of freedom in the locations where the gas inlet and gas outlet are formed is increased.

[0016] (4) In the method for manufacturing the glass base material described in (2) above, the gas introduction step and the gas discharge step may be performed simultaneously.

[0017] According to the above method for manufacturing the glass base material, the gas introduction process and the gas discharge process are performed simultaneously, so corrosive gas is less likely to remain in the discharge pipe that discharges the gas during the gas discharge process. As a result, corrosive gas is less likely to flow from the discharge pipe into the pre-chamber.

[0018] (5) In a method for manufacturing a glass base material according to any of (1) to (4) above, the manufacturing apparatus may be equipped with a gate valve capable of separating the main chamber and the auxiliary chamber, and the gas introduction step and the gas discharge step may be performed with the main chamber and the auxiliary chamber separated by the gate valve.

[0019] According to the above method for manufacturing the glass base material, the main chamber and the auxiliary chamber are separated by a gate valve, making it difficult for corrosive gas to flow from the main chamber to the auxiliary chamber during the gas introduction process and the gas discharge process.

[0020] (6) In the method for manufacturing a glass base material according to any one of (1) to (5) above, the manufacturing apparatus includes a gate valve capable of separating the main chamber and the preliminary chamber, and the gas introduction step and the gas discharge step may be executed in a state where the main chamber and the preliminary chamber communicate with each other through the gate valve.

[0021] According to the above method for manufacturing a glass base material, since the main chamber and the preliminary chamber are not separated by a gate valve, corrosive gas is less likely to remain in the main chamber. Thus, even when it is necessary to open the gate valve during operation, the concentration of corrosive gas in the preliminary chamber is maintained low.

[0022] (7) In the method for manufacturing a glass base material according to (6) above, the gas discharge step may discharge gas from the preliminary chamber and the main chamber.

[0023] According to the above method for manufacturing a glass base material, since gas is discharged from both the preliminary chamber and the main chamber in a state where the main chamber and the preliminary chamber are not separated by a gate valve, the concentration of corrosive gas in the main chamber and the preliminary chamber can be reduced.

[0024] (8) In the method for manufacturing a glass base material according to (6) above, the gas introduction step and the gas discharge step may be performed simultaneously, and the gas discharge step may be a step of discharging gas from the main chamber.

[0025] According to the above method for manufacturing a glass base material, a gas flow is formed in which the gas introduced into the preliminary chamber in the gas introduction step flows into the main chamber and is discharged in the gas discharge step. Thereby, corrosive gas is less likely to flow from the main chamber to the preliminary chamber. Thereby, the concentration of corrosive gas in the preliminary chamber can be reduced.

[0026] (9) In the method for manufacturing a glass base material according to any one of (1) to (8) above, the gas introduced in the gas introduction step may be an inert gas.

[0027] According to the above manufacturing method, an inert gas is introduced during the gas introduction process, making it less likely to react with the glass base material even in high-temperature environments. As a result, the gas introduction process can be carried out immediately after the glass base material manufacturing process is completed, enabling efficient production of the glass base material.

[0028] (10) A glass base material manufacturing apparatus according to one aspect of the present disclosure comprises: a main chamber capable of manufacturing a glass base material with a glass microparticle deposit contained therein; a spare chamber communicating with the main chamber and formed to allow the glass microparticle deposit and the glass base material to be inserted into and removed from the main chamber; and a furnace tube housed inside the main chamber and used for manufacturing the glass base material with the glass microparticle deposit contained therein, wherein the furnace tube has a corrosive gas inlet for introducing a corrosive gas during the sintering of the glass microparticle deposit; the spare chamber has a gas inlet for introducing an inert gas after the glass base material has been manufactured; and either the main chamber or the spare chamber has a gas outlet for discharging gas after the glass base material has been manufactured.

[0029] With the glass base material manufacturing apparatus configured as described above, after the manufacturing process, gas can be introduced into a pre-chamber and the gas can be discharged from at least one of the pre-chamber and the main chamber. Therefore, even if corrosive gas introduced into the furnace tube during the manufacturing of the glass base material leaks out, the inert gas introduced into the pre-chamber will be discharged along with the corrosive gas, thereby reducing the concentration of corrosive gas in the pre-chamber.

[0030] (Details of the embodiments of this disclosure) Specific examples of a glass substrate manufacturing apparatus and manufacturing method according to the embodiments of this disclosure will be described below with reference to the drawings. However, this disclosure is not limited to these examples and is intended to include all modifications within the meaning and scope of the claims as indicated by the claims.

[0031] Figure 1 illustrates a manufacturing apparatus 1 for a glass base material G according to the first embodiment. The manufacturing apparatus 1 manufactures the glass base material G by heating a deposit of glass microparticles. The manufacturing apparatus 1 is equipped with a main chamber 2 and a spare chamber 3.

[0032] The main chamber 2 is capable of manufacturing a glass matrix G with a glass microparticle deposit contained within it. Inside the main chamber 2 is a furnace tube 21 in which the glass matrix G is manufactured with the glass microparticle deposit contained within it. A lid 21a may be provided on the upper part of the furnace tube 21. The lid 21a can close the upper part of the furnace tube 21 during the manufacturing of the glass matrix G. A corrosive gas inlet 21b is formed in the furnace tube 21. A corrosive gas inlet pipe 21c extends from the corrosive gas inlet 21b out of the main chamber 2. The corrosive gas inlet 21b is formed to introduce a corrosive gas during the sintering of the glass microparticle deposit. The corrosive gas is, for example, fluoride gas.

[0033] The spare chamber 3 is formed to allow the insertion and removal of the glass microparticle deposit and the glass base material G. The spare chamber 3 is located above the main chamber 2. The spare chamber 3 has a spare chamber gas inlet 31. The spare chamber gas inlet 31 is located at the bottom of the side of the spare chamber 3. A spare chamber gas inlet pipe 31a is provided at the spare chamber gas inlet 31. The spare chamber gas inlet pipe 31a extends outside the spare chamber 3. The spare chamber gas inlet 31 is formed to introduce an inert gas after the manufacturing of the glass base material G. The spare chamber 3 is provided with a door (not shown) that allows workers or the glass microparticle deposit and glass base material G to be inserted and removed.

[0034] A gas outlet is formed in either the main chamber 2 or the auxiliary chamber 3 to discharge internal gases after the glass base material G is manufactured. The gas outlets in this embodiment include a core tube outlet 21d formed in the core tube 21, a main chamber outlet 22 formed in the main chamber 2, and an auxiliary chamber gas outlet 32 ​​formed in the auxiliary chamber 3.

[0035] A main chamber exhaust pipe 22a is provided at the main chamber exhaust port 22. The main chamber exhaust pipe 22a extends outside the main chamber 2. A core tube exhaust pipe 21e extends from the core tube exhaust port 21d to the outside of the core tube 21 and the main chamber 2.

[0036] A spare chamber gas outlet 32 ​​is provided with a spare chamber gas outlet 32a. The spare chamber gas outlet 32a extends to the outside of the spare chamber 3. The spare chamber gas outlet 32 ​​is formed to discharge gas from inside the spare chamber 3 after the glass base material G has been manufactured. In this embodiment, the spare chamber gas outlet 32 ​​is formed on the upper part of the side surface of the spare chamber 3.

[0037] The auxiliary chamber gas exhaust pipe 32a, the main chamber exhaust pipe 22a, and the core tube exhaust pipe 21e are each equipped with a first flow regulator A, a second flow regulator B, and a third flow regulator C, respectively. The first flow regulator A, the second flow regulator B, and the third flow regulator C can regulate the flow rate of the gas discharged in the auxiliary chamber gas exhaust pipe 32a, the main chamber exhaust pipe 22a, and the core tube exhaust pipe 21e, respectively. The core tube exhaust pipe 21e, the main chamber exhaust pipe 22a, and the auxiliary chamber gas exhaust pipe 32a are connected to a suction pump D. The operation of the suction pump D enables the suction of gas through the core tube exhaust pipe 21e, the main chamber exhaust pipe 22a, and the auxiliary chamber gas exhaust pipe 32a.

[0038] The manufacturing apparatus 1 is equipped with a gate valve 4 that can separate the main chamber 2 and the auxiliary chamber 3. Figure 1 illustrates a state in which the gate valve 4 is closed and the main chamber 2 and the auxiliary chamber 3 are separated. However, during the manufacturing of the glass base material G, the gate valve 4 is open, and in this case, the main chamber 2 and the auxiliary chamber 3 are in communication.

[0039] Next, a method for manufacturing the glass base material G according to the first embodiment will be described. The method for manufacturing the glass base material G comprises a manufacturing process, a gas introduction process, and a gas discharge process. The manufacturing process is a process of manufacturing the glass base material G by sintering the glass fine particle deposits inside the furnace tube 21 while introducing a corrosive gas into the furnace tube 21. During the manufacturing process, the glass base material G is in the main chamber 2 and the gate valve 4 is open. When the manufacturing process is completed, the glass base material G is lifted up and moved to the reserve chamber 3, and the gate valve 4 is closed. The gas introduction process and the gas discharge process are performed with the gate valve 4 closed. Also, during the manufacturing process, the first flow regulator A and the second flow regulator B are closed, and the third flow regulator C is always open.

[0040] The gas introduction process is a process in which gas is introduced into the pre-chamber 3 from the pre-chamber gas inlet 31 after the manufacturing process. The gas introduced in the gas introduction process is preferably an inert gas such as nitrogen (N2) or helium (He).

[0041] The gas discharge process is a process of discharging gas from at least one of the pre-chamber 3 and the main chamber 2. In the first embodiment, since the pre-chamber gas outlet 32 ​​is provided in the pre-chamber 3, the gas is discharged from the pre-chamber 3 during the gas discharge process.

[0042] The gas introduction process begins before the gas discharge process is completed. It is desirable that both the gas introduction and gas discharge processes are performed with the gate valve 4 closed. In this embodiment, the gas introduction and gas discharge processes begin after the gate valve 4 is closed.

[0043] In the first embodiment, the gas introduction process and the gas discharge process are performed simultaneously. During the gas introduction process, gas is introduced into the reserve chamber 3 (arrow I). During the gas discharge process, the first flow regulator A is opened, and the discharge of gas from the reserve chamber 3 begins (arrow II). During both the gas introduction and gas discharge processes, the first flow regulator A remains open throughout the gas introduction process. By performing these processes simultaneously, an airflow is formed inside the reserve chamber 3, as shown by the dashed arrow III, from the reserve chamber gas inlet 31 to the reserve chamber gas outlet 32. As a result, the air inside the reserve chamber 3 is easily discharged from the reserve chamber gas outlet 32.

[0044] In addition, in the gas introduction process and gas discharge process according to the first embodiment, the second flow regulator B and the third flow regulator C may be open or closed.

[0045] During the manufacturing process, a lid 21a is attached to the core tube 21, but corrosive gases may leak from between the support rod and the lid 21a, affecting the glass particle deposition and the glass matrix G. To ensure the safety of workers, it is important to reduce the concentration of corrosive gases in the reserve chamber 3.

[0046] According to the glass base material G manufacturing apparatus 1 and manufacturing method of this embodiment, after the manufacturing process, a gas introduction process is performed to introduce gas into the spare chamber 3, and a gas discharge process is performed to discharge gas from at least one of the spare chamber 3 and the main chamber 2. Therefore, even if corrosive gas introduced into the core tube 21 during the manufacturing of the glass base material G leaks out into the main chamber 2 outside the core tube 21 and mixes into the spare chamber 3, the corrosive gas is discharged together with the gas introduced into the spare chamber 3, thereby reducing the concentration of corrosive gas in the spare chamber 3.

[0047] According to the manufacturing method of the glass base material G of this embodiment, since gas is discharged from the pre-chamber 3, corrosive gas is less likely to remain in the pre-chamber 3, where it is desired to reduce the concentration of corrosive gas.

[0048] In the manufacturing method of the glass base material G of this embodiment, the gas introduction process and the gas discharge process are performed simultaneously, so corrosive gas is less likely to remain in the pre-chamber gas discharge pipe 32a that discharges gas in the gas discharge process.

[0049] In the manufacturing method of the glass base material G of this embodiment, the main chamber 2 and the auxiliary chamber 3 are separated by the gate valve 4, so that corrosive gas is less likely to flow from the main chamber 2 to the auxiliary chamber 3 during the gas introduction process and the gas discharge process.

[0050] In the manufacturing method of the glass base material G of this embodiment, an inert gas is introduced in the gas introduction step, so the introduced gas is less likely to react with the glass base material G, even in high-temperature environments such as near the glass base material G immediately after manufacturing. As a result, the gas introduction step can be performed immediately after the manufacturing process of the glass base material G is completed, so the glass base material G can be manufactured efficiently.

[0051] In the first embodiment, it is desirable that the pre-chamber gas inlet 31 and the pre-chamber gas outlet 32 ​​are located on opposite sides of the pre-chamber 3 and at different heights. This allows the gas introduced from the pre-chamber gas inlet 31 to flow over a wide area of ​​the pre-chamber 3 and be discharged from the pre-chamber gas outlet 32, thus facilitating the discharge of corrosive gases over a wide area from the pre-chamber 3.

[0052] Next, a description of the manufacturing method for the glass base material G according to the second embodiment will be provided. Note that the manufacturing apparatus 1 is the same as in the first embodiment, so its description will be omitted.

[0053] The manufacturing process of the second embodiment is the same as that of the first embodiment, so its explanation will be omitted.

[0054] In the method for manufacturing the glass base material G according to the second embodiment, the gas introduction step and the gas discharge step are performed alternately at least once each. First, as illustrated in Figure 1, with the first flow regulator A closed, gas is introduced into the reserve chamber 3 during the gas introduction step (arrow I). Next, after the gas introduction is stopped, the first flow regulator A is opened and the gas discharge step begins (arrow II). This cycle is repeated alternately at least once each.

[0055] In addition, in the gas introduction and gas discharge processes according to the second embodiment, the second flow regulator B and the third flow regulator C may be open or closed. Furthermore, the gas introduction and gas discharge processes according to the second embodiment are performed with the gate valve 4 closed, similar to the first embodiment.

[0056] In the gas discharge process, it is desirable that the internal pressure of the pre-chamber 3 become a vacuum. For example, if the internal pressure of the pre-chamber 3 becomes 1 / 10 of atmospheric pressure during the gas discharge process, the concentration of corrosive gas in the pre-chamber 3 will also become 1 / 10. If this gas discharge process is performed twice, the concentration of corrosive gas in the pre-chamber 3 will become 1 / 100. In this way, the more cycles are repeated, the lower the concentration of corrosive gas becomes.

[0057] In the manufacturing method of the glass base material G of this embodiment, the gas introduction step and the gas discharge step are performed alternately at least once each. Therefore, since no gas is introduced during the gas discharge step, complex control of the gas introduction step and the gas discharge step is unnecessary. In addition, the degree of freedom is improved in the locations where the auxiliary chamber gas inlet 31 and the auxiliary chamber gas outlet 32 ​​are formed.

[0058] Next, a method for manufacturing the glass base material G according to the third embodiment will be described. Figure 2 illustrates a manufacturing apparatus 1 and manufacturing method for the glass base material G according to the third embodiment. The manufacturing apparatus 1 according to the third embodiment further includes a main chamber gas inlet 23. The main chamber gas inlet 23 is formed to allow the introduction of an inert gas into the main chamber 2, for example, into the furnace tube 21.

[0059] In the method for manufacturing the glass base material G according to the third embodiment, the manufacturing process is the same as that of the first embodiment, so a description will be omitted.

[0060] In the third embodiment, the gas introduction and gas discharge processes are performed with the gate valve 4 open. The gas introduction and gas discharge processes may be performed not only when the glass base material G is housed in the spare chamber 3, but also, for example, when the manufacturing process is completed and the glass base material G has moved from the main chamber 2 to the spare chamber 3. The gas introduction and gas discharge processes may be performed alternately or simultaneously. In the third embodiment, the gas introduction and gas discharge processes are performed simultaneously.

[0061] The gas introduction step according to the third embodiment includes introducing gas from the pre-chamber gas inlet 31 formed in the pre-chamber 3. It is desirable that inert gas be introduced not only from the pre-chamber gas inlet 31 but also from the main chamber gas inlet 23.

[0062] The gas discharge process includes not only discharging the gas from the auxiliary chamber 3 through the auxiliary chamber gas outlet 32, but also discharging the gas from the main chamber 2 through the main chamber outlet 22. In this case, the first flow regulator A and the second flow regulator B are always open during the gas introduction process and the gas discharge process. Furthermore, in this embodiment, the gas discharge process discharges the gas from the core tube 21 via the core tube discharge pipe 21e. In this case, in addition to the first flow regulator A and the second flow regulator B, the third flow regulator C is also always open during the gas introduction process and the gas discharge process.

[0063] In the gas introduction process, inert gas is introduced from the pre-chamber gas inlet 31, and in the gas discharge process, gas is discharged from the pre-chamber gas outlet 32, both occurring simultaneously. Therefore, similar to the first embodiment, an airflow is formed inside the pre-chamber 3, as indicated by the dashed arrow III, from the pre-chamber gas inlet 31 to the pre-chamber gas outlet 32. As a result, the air inside the pre-chamber 3 is easily discharged from the pre-chamber gas outlet 32.

[0064] In the gas introduction process, inert gas is introduced from the main chamber gas inlet 23, and in the gas discharge process, gas is discharged from the main chamber outlet 22, both occurring simultaneously. As a result, an airflow is formed inside the main chamber 2, as shown by the dashed arrow IV, with the gas flowing from the main chamber gas inlet 23 to the main chamber outlet 22. This makes it easier for corrosive gases inside the main chamber 2 to be discharged along with the inert gas, reducing the corrosive gas concentration in the main chamber 2. Consequently, the amount of corrosive gas flowing from the main chamber 2 to the auxiliary chamber 3 is also reduced, resulting in a lower corrosive gas concentration in the auxiliary chamber 3.

[0065] When the gas introduction and gas discharge processes are performed alternately, and inert gas is introduced from the spare chamber gas inlet 31 and the main chamber gas inlet 23, first, the first flow regulator A, second flow regulator B, and third flow regulator C are closed. Next, once the introduction of inert gas from the spare chamber gas inlet 31 and the main chamber gas inlet 23 has stopped, the first flow regulator A, second flow regulator B, and third flow regulator C are opened, and gas discharge begins. Once gas discharge is complete and inert gas is to be introduced again, the first flow regulator A, second flow regulator B, and third flow regulator C are closed.

[0066] In the manufacturing method of the glass base material G of this embodiment, the main chamber 2 and the auxiliary chamber 3 are not separated by the gate valve 4, so corrosive gases are less likely to remain in the main chamber 2. As a result, even if it becomes necessary to open the gate valve 4 during operation, the concentration of corrosive gases in the auxiliary chamber 3 remains low.

[0067] According to the manufacturing method of the glass base material G of this embodiment, since the main chamber 2 and the auxiliary chamber 3 are not separated by the gate valve 4, gas is discharged from both the main chamber 2 and the auxiliary chamber 3, thus reducing the concentration of corrosive gas in the main chamber 2 and the auxiliary chamber 3.

[0068] Figure 3 illustrates a manufacturing apparatus 1 and manufacturing method for a glass base material G according to the fourth embodiment. In the manufacturing apparatus 1 for a glass base material G according to the fourth embodiment, the pre-chamber gas inlet 31 is formed in the upper part of the pre-chamber 3.

[0069] In the manufacturing method of the glass base material G according to the fourth embodiment, the manufacturing process is the same as that of the first embodiment, so a description will be omitted.

[0070] The gas introduction and gas discharge processes according to the fourth embodiment are performed with the gate valve 4 open, similar to the third embodiment. The gas introduction and gas discharge processes according to the fourth embodiment may be performed not only when the glass base material G is housed in the spare chamber 3, but also, for example, during the manufacturing process or when the glass base material G has moved from the main chamber 2 to the spare chamber 3 after the manufacturing process has finished. The gas introduction and gas discharge processes according to the fourth embodiment are performed simultaneously.

[0071] The gas introduction step according to the fourth embodiment includes introducing an inert gas from a pre-chamber gas inlet 31 formed in the pre-chamber 3.

[0072] The gas discharge process according to the fourth embodiment is a process of discharging the gas from the main chamber 2 through the main chamber outlet 22. In this case, when the gas introduction process and the gas discharge process are started, the first flow regulator A and the third flow regulator C are closed, and the second flow regulator B is opened, and the second flow regulator B remains open while the gas introduction process and the gas discharge process are performed.

[0073] In this case, gas is introduced into the auxiliary chamber 3 and discharged from the main chamber 2, so the gas flows from the auxiliary chamber 3 towards the main chamber 2 (arrow V). As a result, the corrosive gas introduced into the core tube 21 has difficulty flowing from the main chamber 2 to the auxiliary chamber 3.

[0074] In the manufacturing method of the glass base material G of this embodiment, a gas flow is formed in which the gas introduced into the preliminary chamber 3 in the gas introduction step flows to the main chamber 2 and is discharged in the gas discharge step. As a result, corrosive gases are less likely to flow from the main chamber 2 to the preliminary chamber 3. This makes it possible to reduce the concentration of corrosive gases in the preliminary chamber 3.

[0075] Although this disclosure has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of this disclosure. Furthermore, the number, position, shape, etc. of the components described above are not limited to the embodiments described above and can be changed to a number, position, shape, etc. that is suitable for carrying out this disclosure.

[0076] For example, the arrangement of the main chamber 2 and the auxiliary chamber 3 is not limited to the examples of this embodiment. Furthermore, the arrangement of the inlet and outlet formed in the main chamber 2 or the auxiliary chamber 3 is not limited to the examples of this embodiment. [Explanation of Symbols]

[0077] 1 Manufacturing equipment 2 Main room 3. Spare Room 4 Gate valve 21 Core Tubes 21a Lid 21b Corrosive gas inlet 21c Corrosive gas introduction pipe 21d Core tube outlet 21e Core Tube Discharge Pipe 22 Main room outlet 22a Main room exhaust pipe 23 Main chamber gas inlet 31. Gas inlet for spare room 31a Pre-chamber gas inlet pipe 32. Pre-chamber gas outlet 32a Pre-chamber gas exhaust pipe

Claims

1. A main chamber capable of manufacturing a glass base material while containing a deposit of glass microparticles inside, A preliminary chamber, which is in communication with the main chamber and is formed to allow the insertion and removal of the glass microparticle deposit and the glass base material, A manufacturing apparatus comprising the above-mentioned glass base material, a method for manufacturing the glass base material, Inside the main chamber is a furnace tube that manufactures the glass base material while containing the glass microparticle deposit inside. A manufacturing process for producing the glass base material by introducing a corrosive gas into the furnace tube and sintering the glass particle deposits inside the furnace tube, Following the manufacturing process, a gas introduction process is performed to introduce gas into the pre-chamber, The manufacturing process is followed by a gas discharge process in which gas is discharged from at least one of the pre-chamber and the main chamber. The gas introduction process is started before the end of the gas discharge process. A method for manufacturing glass substrates.

2. The aforementioned gas discharge process is a process of discharging gas from the aforementioned pre-chamber. A method for manufacturing a glass base material according to claim 1.

3. The gas introduction step and the gas discharge step are performed alternately at least once each. The method for manufacturing a glass base material according to claim 2.

4. The gas introduction process and the gas discharge process are performed simultaneously. The method for manufacturing a glass base material according to claim 2.

5. The manufacturing apparatus is equipped with a gate valve capable of separating the main chamber and the auxiliary chamber. With the main chamber and the auxiliary chamber separated by the gate valve, the gas introduction process and the gas discharge process are performed. A method for manufacturing a glass base material according to claim 1.

6. The manufacturing apparatus is equipped with a gate valve capable of separating the main chamber and the auxiliary chamber. With the gate valve in place, the main chamber and the auxiliary chamber are in communication while the gas introduction process and the gas discharge process are performed. A method for manufacturing a glass base material according to claim 1.

7. The gas discharge process involves discharging gas from the pre-chamber and the main chamber. A method for manufacturing a glass substrate according to claim 6.

8. The gas introduction process and the gas discharge process are performed simultaneously. The aforementioned gas discharge process is a process of discharging gas from the main chamber. A method for manufacturing a glass substrate according to claim 6.

9. The gas introduced in the aforementioned gas introduction process is an inert gas. A method for manufacturing a glass substrate according to any one of claims 1 to 8.

10. A main chamber capable of manufacturing a glass base material while containing a deposit of glass microparticles inside, A preliminary chamber, which is in communication with the main chamber and is formed to allow the insertion and removal of the glass microparticle deposit and the glass base material, The furnace comprises a core tube housed inside the main chamber, which houses the glass microparticle deposits and is used to manufacture the glass base material, The furnace tube has a corrosive gas inlet formed therein for introducing corrosive gas during the sintering of the glass particle deposit. The aforementioned pre-chamber has a gas inlet formed therein for introducing an inert gas after the glass base material has been manufactured. A gas outlet for discharging gas after the manufacturing of the glass base material is formed in either the main chamber or the auxiliary chamber. A manufacturing device for glass base materials.

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