JP5953767B2 - Method for producing glass particulate deposit and method for producing glass base material - Google Patents

Description

  The present invention is a glass for producing a glass fine particle deposit by depositing glass fine particles on a starting rod by VAD method (vapor phase axis attaching method), OVD method (external attaching method), MMD method (multi-burner multilayer attaching method) or the like. The present invention relates to a method for producing a fine particle deposit and a method for producing a glass base material by heating the glass fine particle deposit to make it transparent.

  As a conventional method for producing a glass base material, there are a deposition step for producing a glass particulate deposit by an OVD method, a VAD method or the like, and a transparency step for producing a transparent glass preform by heating the glass particulate deposit. (For example, refer patent documents 1-3).

  In the manufacturing method of Patent Document 1, glass raw material gas is heated and vaporized, and the glass raw material gas is guided to a glass fine particle forming burner by piping under reduced pressure. For example, the temperature of the piping is 55 ° C., and the heat resistance temperature is about 70 ° C. This makes it possible to use piping made of a vinyl chloride material.

  The manufacturing method of Patent Document 2 starts the deposition of glass fine particles after discarding the glass raw material gas for a predetermined time prior to the start of the deposition of the fine glass particles, and then discards the raw material gas, the volume of the piping, the pressure in the piping, and the piping. Is set to satisfy a predetermined relationship. Thereby, the generation of bubbles and cloudiness in the glass base material is avoided. The piping temperature is 82 ° C. or 85 ° C.

  In the manufacturing method of Patent Document 3, as a means for suppressing irregularities generated on the surface of the glass fine particle deposit, a conduit from a source gas generator for supplying source gas to a burner is formed at 90 ° C. over the entire length using a heater and a heat insulating material. This is what is held above.

  Patent Document 4 describes a method for suppressing the spread of the flame by introducing gas into the inner periphery of the hood installed at the tip of the burner flame as a means for increasing the raw material yield.

JP 2004-161555 A JP 2006-342031 A JP 2003-165737 A Japanese Patent Laid-Open No. 7-144927

  However, in the method for producing a glass base material described in Patent Documents 1 to 4, there is a limit to the ratio of the amount of glass fine particles deposited to the amount of glass raw material gas supplied. That is, it is difficult to efficiently attach the generated glass fine particles to the starting rod and the glass fine particle deposit.

  An object of the present invention is to provide a method for producing a glass fine particle deposit and a method for producing a glass base material, which can improve the adhesion efficiency of the produced glass fine particles to a starting rod and a glass fine particle deposit.

The method for producing a glass fine particle deposit according to the present invention that can solve the above-mentioned problem is to heat and vaporize a liquid glass raw material contained in a raw material container to obtain a glass raw material gas,
The glass raw material gas is led from the raw material container to a glass fine particle generating burner by piping, and the glass raw material gas is ejected from the glass fine particle generating burner,
Deposition step of depositing glass particles generated by flame decomposition reaction (thermal decomposition reaction, flame hydrolysis reaction, thermal oxidation reaction, etc.) of the ejected glass source gas on a starting rod in a reaction vessel to form a glass particle deposit A method for producing a glass particulate deposit comprising:
In the deposition step, at least a part of the piping from the raw material container to the glass particulate generation burner is controlled to a temperature of 100 ° C. or more by a heating element, and the end of the glass particulate generation burner on the piping side The region of 1/3 or less in the longitudinal direction is controlled to a temperature of 100 ° C. or more by a heating element.

  In the deposition step, at least a part of the pipe from the raw material container to the glass fine particle generating burner, and a region of 1/3 or less in the longitudinal direction from the end of the pipe in the glass fine particle generating burner Is preferably controlled to a temperature of 150 ° C. or higher by a heating element. More preferably, the temperature is controlled to 260 ° C. or higher, more preferably 300 ° C. or higher.

  In addition, the method for producing a glass base material according to the present invention is characterized in that the glass fine particle deposit produced by the method for producing a glass fine particle deposit is heated to become a glass preform through a transparentizing step. It is said.

  Moreover, it is preferable to deposit the glass fine particles in the deposition step by any one of the VAD method, the OVD method, and the MMD method.

  According to the method for producing a glass particulate deposit and the method for producing a glass base material according to the present invention, at least a part of the piping from the raw material container to the glass particulate generation burner is controlled to a temperature of 100 ° C. or more by the heating element. The temperature of the raw material gas in the glass particulate generation burner is controlled by a heating element to a temperature of 1/3 or less in the longitudinal direction from the end of the pipe side in the glass particulate generation burner by a heating element. Can be prevented.

  By increasing the temperature of the raw material gas flowing in the glass fine particle generating burner, the flame hydrolysis reaction of the raw material gas is promoted in the burner flame, and the number of glass fine particles generated in the flame is increased. The outer diameter also increases. In addition, the increase in particle diameter promotes aggregation (bonding between particles) due to turbulent diffusion. By these effects, the inertial force of the glass fine particles is increased, the glass fine particles are easily detached from the flow of the flame gas, and the adhesion efficiency of the glass fine particles to the starting rod and the glass fine particle deposit can be improved.

It is a block diagram of an example of the manufacturing apparatus which enforces the manufacturing method of the glass particulate deposits concerning the present invention. It is a schematic diagram explaining the behavior at the time of glass particulates depositing on a glass particulate deposit. It is the graph which changed the temperature of the raw material gas in a part of longitudinal direction in gas supply piping, changing Reynolds number. It is a graph which shows the temperature change of the raw material gas in a part of longitudinal direction in the gas supply piping and the burner for glass particulate generation.

  Hereinafter, a method for producing a glass fine particle deposit and a method for producing a glass base material according to an embodiment of the present invention will be described with reference to the drawings. In the following, the VAD method will be described as an example, but the present invention is not limited to the VAD method. The present invention can also be applied to other methods for producing a glass fine particle deposit such as an OVD method and an MMD method.

  As shown in FIG. 1, a manufacturing apparatus 10 that performs the method for manufacturing a glass fine particle deposit according to the present embodiment deposits glass fine particles by the VAD method. The starting rod 13 is attached to the lower end of the support rod 12. An exhaust pipe 21 is attached to the side surface of the reaction vessel 11.

  The upper end of the support bar 12 is gripped by the lifting / lowering rotating device 15 and is lifted / lowered by the lifting / lowering rotating device 15 together with the rotation. The raising / lowering rotation device 15 is controlled by the control device 16 so that the outer diameter of the glass fine particle deposit 14 is uniform. Below the reaction vessel 11, a cladding burner 18, which is a glass fine particle generating burner, is disposed. The clad burner 18 ejects glass fine particles 20 toward the starting rod 13 to form a glass fine particle deposit 14. Further, the glass fine particles 20 in the reaction vessel 11 that have not adhered to the starting rod 13 and the glass fine particle deposit 14 are exhausted through the exhaust pipe 21.

  A raw material gas and a flame forming gas are supplied to the cladding burner 18 by a gas supply device 19. The cladding burner 18 is a multi-tube burner such as an eight-fold tube. In FIG. 1, the illustration of a gas supply device that supplies the flame forming gas is omitted.

The cladding burner 18 is charged with SiCl ₄ as a source gas, H ₂ and O ₂ as a flame forming gas, and N ₂ as a burner seal gas. In the oxyhydrogen flame of the cladding burner 18, glass fine particles 20 are generated by a flame hydrolysis reaction, and the glass fine particles 20 are deposited on the starting rod 13 to produce a glass fine particle deposit 14 having a predetermined outer diameter.

  The gas supply device 19 includes a raw material container 22 for storing the liquid raw material 28, an MFC 23 for controlling the supply flow rate of the raw material gas, a gas supply pipe 25 for guiding the raw material gas to the cladding burner 18, a raw material container 22, the MFC 23, and a gas supply pipe 25. The temperature control booth 24 keeps a part of the temperature above a predetermined temperature.

  The liquid raw material 28 in the raw material container 22 is controlled to a temperature equal to or higher than the boiling point in the temperature control booth 24, vaporized in the raw material container 22, and the supply amount of the raw material gas supplied to the cladding burner 18 by the MFC 23 is controlled. The Note that the control of the raw material gas supply amount by the MFC 23 is performed based on a command value from the control device 16.

  In the method for producing a glass particulate deposit according to the present embodiment, at least a part of the gas supply pipe 25 from the temperature control booth 24 to the cladding burner 18 is controlled to a temperature of 100 ° C. or more by a tape heater 26 as a heating element. Then, the region A of 1/3 or less in the longitudinal direction from the end on the gas supply pipe 25 side in the cladding burner 18 is controlled to a temperature of 100 ° C. or more by the heating element. For example, a tape heater is used as the heating element.

  In order to promote the flame hydrolysis reaction of the raw material gas in the burner flame, at least part of the gas supply pipe 25 including the connection portion with the cladding burner 18 is controlled to be 100 ° C. or higher. Although good, you may control the whole piping so that it may become 100 degreeC or more.

  Further, the temperature control region of the gas supply pipe 25 and the temperature in the region A that is 1/3 or less in the longitudinal direction from the end of the cladding burner 18 on the gas supply pipe 25 side are controlled to be 150 ° C. or more. It is preferable that the temperature is controlled to be 260 ° C. or higher, more preferably 300 ° C. or higher.

  By doing in this way, the temperature of the raw material gas ejected from the raw material container 22 into the burner flame through the cladding burner 18 is increased, and the flame hydrolysis reaction of the raw material gas in the burner flame can be promoted.

  When the flame hydrolysis reaction is promoted in the burner flame, the number of glass fine particles generated in the flame increases. Further, since the growth of the glass fine particles proceeds, the outer diameter of the glass fine particles also increases. Furthermore, when the particle diameter increases, aggregation (bonding between particles) due to turbulent diffusion is promoted. Due to these effects, the inertial force of the glass fine particles in the burner flame is increased, and the glass fine particles are easily detached from the flow of the flame gas (see FIG. 2), and the glass fine particles 20 to the starting rod 13 and the glass fine particle deposit 14 are obtained. The adhesion efficiency of can be improved.

  As for the material of the gas supply pipe 25, when the gas supply pipe 25 is held at a temperature of less than 200 ° C., the material of the gas supply pipe 25 may be fluororesin (Teflon (registered trademark)), but it is 200 ° C. or more. When the temperature is maintained, the material of the gas supply pipe 25 is preferably a metal such as SUS having excellent heat resistance. Further, the gas supply pipe 25 from the temperature control booth 24 to the cladding burner 18 and the outer periphery of the region A in the longitudinal direction of 1/3 or less from the end of the cladding burner 18 on the gas supply pipe 25 side is a heating element. A tape heater 26 is wound around. The tape heater 26 is a flexible heater in which an ultra fine stranded wire of a metal heating element or a carbon fibrous surface heating element is covered with a protective material. When the tape heater 26 is energized, the gas supply pipe 25 and the cladding burner 18 are heated.

  Further, the inner diameter of the gas supply pipe 25 is set so that the Reynolds number (Re number) of the source gas flowing in the gas supply pipe 25 and the cladding burner 18 is 2000 or more, preferably 4000 or more, more preferably 8000 or more. design. As a result, the flow of the raw material gas in the gas supply pipe 25 is turbulent, and the raw material gas is efficiently heated in the gas supply pipe 25 to easily increase the temperature. FIG. 3 shows the temperature of the raw material gas flowing in the gas supply pipe 25 when the entire length of the gas supply pipe 25 is heated to a constant value of 140 ° C. FIG. 3 shows that the higher the Re number, the easier the source gas flowing in the gas supply pipe 25 is heated.

  In addition, it is more preferable that the heat insulation tape 27 which is a heat insulating material is wound around the outer periphery of the location where the tape heater 26 is wound. When the heat insulating tape 27 is wound, the power consumption can be kept low.

  The temperature distribution in the longitudinal direction of the gas supply pipe 25 and the cladding burner 18 is preferably controlled so that the temperature increases from the raw material container 22 toward the cladding burner 18. Thereby, since the flow velocity of the raw material gas flowing from the raw material container 22 toward the cladding burner 18 is accelerated, the glass fine particles 20 generated in the flame are aggregated (interparticle bonding) by turbulent diffusion, and the bonded particle group Is easily separated from the flame gas flow G, and the adhesion efficiency of the glass fine particles 20 to the starting rod 13 and the glass fine particle deposit 14 can be further improved. Specifically, the deposition efficiency of the glass fine particles 20 can be increased by setting the temperature gradient of the gas supply pipe 25 to 5 ° C./m or more, preferably 15 ° C./m or more, more preferably 25 ° C./m or more. it can.

The manufacturing procedure of the glass fine particle deposit and the glass base material will be described.
(Deposition process)
As shown in FIG. 1, the support rod 12 is attached to the lifting / lowering rotation device 15, and the starting rod 13 attached to the lower end of the support rod 12 is placed in the reaction vessel 11. Next, while the starting rod 13 is rotated by the elevating and rotating device 15, the raw material gas is chemically changed into the glass fine particles 20 by the flame hydrolysis reaction in the oxyhydrogen flame formed by the cladding burner 18, and the starting rod 13 is made of glass. Fine particles 20 are deposited.

  At this time, at least part of the gas supply pipe 25 from the temperature control booth 24 to the clad burner 18 including the connection portion with the clad burner 18 and the end of the clad burner 18 on the gas supply pipe 25 side in the longitudinal direction. The region A which is 1/3 or less of the above is controlled by the tape heater 26 so that the temperature becomes 100 ° C. or higher.

  In order to further promote the flame hydrolysis reaction in the burner flame, the region A that is 1/3 or less in the longitudinal direction from the end of the gas supply pipe 25 and the gas supply pipe 25 side of the cladding burner 18 is 150 ° C. or higher. The temperature is preferably controlled to be 260 ° C. or higher, more preferably 300 ° C. or higher. By doing so, the adhesion efficiency of the glass fine particles 20 generated in the flame of the cladding burner 18 to the starting rod 13 and the glass fine particle deposit 14 can be increased.

  The glass fine particle deposit 14 in which the glass fine particles 20 are deposited on the starting rod 13 is pulled up by the elevating and rotating device 15 in accordance with the growth rate of the lower end portion of the glass fine particle deposit 14.

(Transparent process)
Next, the obtained glass fine particle deposit 14 is heated to 1100 ° C. in a mixed atmosphere of an inert gas and a chlorine gas, and then heated to 1550 ° C. in a He atmosphere to perform transparent vitrification. Such a glass base material is repeatedly manufactured.

The behavior of the glass fine particles 20 in the flame gas flow G will be briefly described.
As shown in FIG. 2, a flame gas flow G containing a raw material gas such as SiCl ₄ formed by the cladding burner 18 hits the glass fine particle deposit 14, and its flowing direction abruptly becomes a glass fine particle deposit. 14 turns in the outer peripheral direction.

  On the other hand, the glass fine particles 20 generated in the flame gas flow G flow along the flame gas flow G, and the inertial force thereof is determined by the Stokes number of the glass fine particles 20. The Stokes number is proportional to the square of the particle diameter and the flow velocity of the particle. As the Stokes number increases, the inertial force of the glass fine particle 20 increases and the straightness of the glass fine particle 20 increases.

  When the flame gas flow G hits the glass fine particle deposit 14 and its flow direction suddenly changes in the outer peripheral direction of the glass fine particle deposit 14, the glass fine particle 20A having a large inertia force has high straightness, and thus directly collides with the glass fine particle deposit 14. To do. However, since the glass fine particles 20B having a small inertia force flow along the flame gas flow G, they flow away in the outer peripheral direction of the glass fine particle deposit 14. Accordingly, it is important how to increase the inertial force of the glass fine particles 20.

  As described above, at least a part of the gas supply pipe 25 from the temperature control booth 24 to the cladding burner 18 and the region A of 1/3 or less in the longitudinal direction from the end of the cladding burner 18 on the gas supply pipe 25 side, The temperature is controlled to 100 ° C. or higher by the tape heater 26 which is a heating element.

  Moreover, the heating range of the cladding burner 18 may be heated within a range of 1/3 or less in the longitudinal direction from the end on the gas supply pipe 25 side. Heating a range wider than 1/3 has no effect of further increasing the temperature of the raw material gas flowing in the burner. This is because the temperature is sufficiently increased in a range other than 1/3 from the end of the cladding burner 18 on the gas supply pipe 25 side due to radiant heat from the flame formed by the burner. The optimum heating range is determined by the burner structure and the structure of the reaction vessel, etc. However, if the region less than 1/3 from the end of the clad burner 18 on the gas supply pipe 25 side is heated, it will be roughly what kind of equipment structure. Even so, there is an effect of keeping the temperature of the raw material gas flowing in the burner at a high temperature.

  As a result, the raw material gas ejected from the cladding burner 18 is accelerated in the flame hydrolysis reaction in the burner flame.

  When the flame hydrolysis reaction is promoted in the burner flame, the number of glass fine particles 20 generated in the flame increases. Further, since the growth of the glass fine particles proceeds, the outer diameter of the glass fine particles also increases. Furthermore, the increase in particle diameter promotes aggregation (bonding between particles) due to turbulent diffusion. Due to these effects, the inertia force of the glass fine particles 20 in the burner flame is increased, and the glass fine particles 20 are easily detached from the flow of the flame gas, and the adhesion efficiency of the glass fine particles 20 to the starting rod 13 and the glass fine particle deposit 14 is improved. Can be improved.

  Further, when the temperature of the source gas flowing in the gas supply pipe 25 and the cladding burner 18 rises, the volume of the source gas expands, and the flow rate of the glass particulates 20 generated in the burner flame also increases. As described above, the inertial force of the glass fine particles 20 flowing along the flame gas flow G is determined by the Stokes number. Since the Stokes number is proportional to the flow velocity of the particles, when the raw material gas temperature in the cladding burner 18 rises and the flow velocity of the glass fine particles 20 increases, the inertial force of the glass fine particles 20 increases. With these effects, the adhesion efficiency of the glass fine particles 20 to the starting rod 13 and the glass fine particle deposit 14 can be improved.

Next, an embodiment of the method for producing a glass fine particle deposit and a glass base material of the present invention will be described. In both Examples and Comparative Examples, a glass fine particle deposit is manufactured using the following materials.
· Starting rod; diameter 20 mm, the input gas into the quartz glass cladding burner length 1000 mm; material gas _... SiCl 4 _(1~7SLM), flame formation gas _{... H 2 (100~150SLM), O} 2 (100~ 150 SLM), burner seal gas ... N ₂ (20-30 SLM)

  Glass fine particles are deposited by the VAD method. The obtained glass fine particle deposit is heated to 1100 ° C. in a mixed atmosphere of an inert gas and a chlorine gas, and then heated to 1550 ° C. in a He atmosphere to perform transparent vitrification.

In the deposition step described above, the piping temperature A (° C.) and the burner temperature B (° C.) are appropriately selected, and the raw material yield X (%) of the glass fine particles is evaluated. The raw material yield X is the mass ratio of the glass fine particles actually deposited on the starting rod and the glass fine particle deposit to the SiO ₂ mass in the case where the SiCl ₄ gas to be added chemically reacts with 100% SiO ₂ . The pipe temperature A is the outer peripheral temperature of the gas supply pipe in the vicinity of the burner. The burner temperature B is the outer peripheral temperature at a position 1/3 in the longitudinal direction from the end of the cladding burner on the gas supply pipe side. In Example 1-5, the area | region from the edge part by the side of the gas supply pipe in a cladding burner to 1/3 of a longitudinal direction is heated, and in Example 6, it is long from the edge part by the side of the gas supply pipe in a cladding burner. Heat up to 1/8 of the direction.
As a result, the results shown in Table 1 are obtained.

As is clear from Table 1, Examples 1 to 6 in which the pipe temperature A and the burner temperature B are 100 ° C. or higher are the raw material yield X is 55% or higher, and the higher the pipe temperature A and the burner temperature B, the higher the raw material yield. The rate X increases. In particular, in Example 4 in which the pipe temperature and the burner temperature are 300 ° C., that is, the pipe temperature and the burner temperature are 242.4 ° C. higher than the standard boiling point of SiCl _{4 as} the raw material gas, the raw material yield X is 67%. In Example 5, the temperature gradient in the longitudinal direction of the gas supply pipe and the clad burner is increased from the raw material container side to the clad burner side with an inclination of 70 ° C./m, and the burner temperature is 330 ° C., that is, the burner temperature. Is 272.4 ° C. higher than the normal boiling point of SiCl ₄ which is the source gas. The effect of imparting a temperature gradient in the longitudinal direction of the gas supply pipe and the cladding burner promotes turbulent diffusion of the glass particles in the flame, and the raw material yield X jumps up to 69%. In Example 6, the piping temperature is set to 300 ° C., the heating range of the burner is set to 1/8, and the outer peripheral temperature at the position of 1/3 in the longitudinal direction from the end of the burner on the gas supply piping side is set to 290 ° C. Comparing Example 4 and Example 6, by reducing the heating range of the burner from 1/3 to 1/8, the raw material yield X is slightly reduced, but the raw material yield is almost equivalent. Recognize.
On the other hand, in Comparative Examples 1 to 3 in which the burner is not heated, the burner temperature B is less than 100 ° C., and the raw material yield X is reduced to 50% or less. In particular, in Comparative Example 3 in which the piping temperature is 80 ° C. and the burner temperature is 65 ° C., the raw material yield X is reduced to 47%. In Examples 1 to 6 and Comparative Examples 1 to 3, the burner temperature B is substantially equal to the raw material gas temperature charged into the burner.

  FIG. 4 is a graph showing the temperature change of the raw material gas in a part in the longitudinal direction in the gas supply pipe and in the glass fine particle generating burner. The data of the broken line is the case where the entire length of the gas supply pipe is heated to 200 ° C., but the burner is not heated. In this case, it can be seen that the raw material gas temperature is lowered in the burner. On the other hand, in the solid line data, the entire length of the gas supply pipe and the 1/3 region in the longitudinal direction from the end of the burner on the gas supply pipe side are heated to 200 ° C. In this case, it can be seen that the temperature of the raw material gas flowing in the burner does not decrease.

  In addition, the manufacturing method of the glass fine particle deposit body and glass base material of this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. For example, in the present embodiment, the case where the glass fine particle deposit is manufactured by the VAD method in the deposition step has been described as an example, but all other glass fine particle deposits and glass using flame decomposition reaction such as the OVD method and the MMD method are used. It is effective for the manufacturing method of the base material.

In this embodiment, only SiCl ₄ is used as the source gas. However, the core glass synthesis using SiCl ₄ and GeCl ₄ is also effective in improving the source yield. A similar effect can be obtained with a source gas other than SiCl ₄ .

  In addition, the material, shape, dimension, numerical value, form, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

  DESCRIPTION OF SYMBOLS 10 ... Manufacturing apparatus, 11 ... Reaction container, 12 ... Support rod, 13 ... Departure rod, 14 ... Glass particulate deposit, 15 ... Elevating and rotating device, 16 ... Control device, 18 ... Burner for clad, 19 ... Gas supply device, 20 ... Glass fine particles, 22 ... Raw material container, 23 ... MFC, 24 ... Temperature control booth, 25 ... Gas supply piping, 26 ... Tape heater (heating element), 27 ... Heat insulation tape

Claims (6)

The liquid glass raw material contained in the raw material container is heated and vaporized to form a glass raw material gas,
The glass raw material gas is led from the raw material container to a glass fine particle generating burner by piping, and the glass raw material gas is ejected from the glass fine particle generating burner,
A method for producing a glass particulate deposit comprising a deposition step of depositing glass particulate produced by a flame decomposition reaction of the jetted glass raw material gas on a starting rod in a reaction vessel to form a glass particulate deposit,
In the deposition step, at least a part of the piping from the raw material container to the glass particulate generation burner is controlled to a temperature of 150 ° C. or more by a heating element, and the end of the glass particulate generation burner on the piping side A method for producing a glass particulate deposit, wherein only a region of 1/3 or less in the longitudinal direction is controlled to a temperature of 150 ° C. or more by a heating element. A method for producing a glass particulate deposit according to claim 1,
The glass raw material gas is only one kind, and the method for producing a glass particulate deposit. A method for producing a glass particulate deposit according to claim 1 or 2 ,
In the deposition step, at least a part of the pipe from the raw material container to the glass fine particle generating burner is controlled to a temperature of 260 ° C. or higher by a heating element, and the end of the glass fine particle generating burner on the pipe side A method for producing a glass particulate deposit, wherein only a region of 1/3 or less in the longitudinal direction is controlled to a temperature of 260 ° C. or more by a heating element. A method for producing a glass particulate deposit according to claim 1 or 2 ,
In the deposition step, at least a part of the piping from the raw material container to the glass particulate generation burner is controlled to a temperature of 300 ° C. or more by a heating element, and the end of the glass particulate generation burner on the piping side A method for producing a glass particulate deposit, wherein only a region of 1/3 or less in the longitudinal direction is controlled to a temperature of 300 ° C. or more by a heating element.   The glass fine particle deposit produced by the method for producing a glass fine particle deposit according to any one of claims 1 to 4 is heated to become a glass base material through a transparentization step. Manufacturing method of glass base material. It is a manufacturing method of the glass base material according to claim 5,
The method for producing a glass base material, characterized in that the glass fine particles are deposited in the deposition step by any one of a VAD method, an OVD method, and an MMD method.

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