JP2000211928A - Silica glass manufacturing equipment - Google Patents

Abstract

(57) [Problem] To provide a burner in which a main component gas and a second component gas are mixed and sent to a burner, the two are efficiently mixed at the time of mixing, and the mixing ratio of both is accurately set. The purpose is to be kept as value. When a main component gas obtained by vaporizing a silica glass raw material and a second component gas or the like are mixed at connection portions A to D of a line, particularly at a connection portion where the flow rate of the main component gas is small,
In the form of a double pipe structure in which a connection small diameter portion K of the main component gas passage is inserted at the center of the connection large diameter portion H of the second component gas passage,
By mixing the main component gas toward the center of the cross section of the flow path of the second component gas, the mixing efficiency is improved. In addition, the temperature controllers 15 to 19 for preventing gas from condensing in the line are controlled by PID control to prevent a defective mixture component ratio due to expansion and contraction of gas volume such as on / off control. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a silica glass fiber preform for optical communication and a silica glass preform to be used as an LSI photomask substrate, for example.

[0002]

2. Description of the Related Art Conventionally, for example, in the production of a fiber preform for optical communication, silicon tetrachloride (SiCl
₄ ) By vaporizing the doping compound for controlling the refractive index and causing a flame hydrolysis reaction in an oxyhydrogen flame, the silica fine particles and the fine particles of the doped material are deposited and deposited on a seed rod. Manufactured but silicon tetrachloride (Si
The vapor of Cl ₄ ) and the vapor of the doping compound are usually produced as main component gases in the respective evaporators, sent into the ventilation passage through the flow controller, and mixed with the second component gas in the middle of the ventilation passage. The mixed gas is sent to a burner for causing a reaction.

[0003] At this time, the structure of a connecting portion such as an air passage through which the main component gas flows and a second component gas passage through which the second component gas flows is, for example, a connecting structure called a cheese union as shown in FIG. Is common.

[0004] In addition, the temperature of the evaporator is set at 10 ° C. in a line pipe such as an air passage through which the main component gas flows or a flow controller.
The temperature is maintained at about 15 ° C. higher to prevent gas condensation, and the line piping through which the second component gas flows is also equal to or greater than the main component gas line until mixed with the main component gas. Is maintained at the temperature described above to prevent condensation when mixed with the main component gas. Further, in the mixed gas line through which the mixed gas flows, the dew point tends to be lower as the ratio of the second component gas is higher, but this line piping is also maintained at the same temperature as the main component gas line. .

[0005]

By the way, in the production of an optical fiber preform, a plurality of burners are used from the center to the outer periphery of the deposited core in order to give the core rod optical characteristics such as a refractive index distribution. In particular, the burner corresponding to the center where optical characteristics are regarded as important, the main component gas flow rate and the second component gas flow rate are those having the smallest flow rates as compared with other burners. Despite the use of the 1/4 inch size smallest diameter pipe, the number of Reynolds nozzles indicating the flow state is in a laminar flow state of about 1 to 10 or less. Flows in a two-layer state at the junction of
There was a problem that mixing did not proceed easily.

[0006] In particular, when the set value of the gas flow rate changes, a stagnant flow zone may be formed in the pipe, and as a result, the main component gas and the second gas at the burner reaction point may be disturbed.
There is a problem that the component ratio of the component gas changes every moment, and the optical characteristics of the manufactured preform change in the longitudinal direction.

[0007] The temperature of the main component gas line, the second gas component gas line, the line piping of the mixed gas line, and the like is maintained at a dew point temperature or higher to prevent the main component gas from condensing. Such a heating mechanism is generally configured such that a temperature sensor is fixed to the surface of a pipe, an electric heater is mounted on the pipe, and the temperature of the heater is controlled by an on / off controller. When an on-off controller is used for a flow pipe, the volume of the gas line expands and contracts each time the on-off operation is performed, and the effect of expansion and contraction due to temperature fluctuations rather than forced convection due to a given pressure difference Natural convection is dominant. As a result, even if the main component gas flow rate and the second component gas flow rate are precisely controlled by the respective flow controllers, the mixing supplied to the burner is controlled. As described above, the composition ratio and the flow rate of the main component gas and the second component gas at the burner reaction point change every moment, and the optical characteristics of the manufactured preform change in the longitudinal direction. There was a defect.

Accordingly, it is an object of the present invention to efficiently mix a main component gas and a second component gas, and to supply the mixture to a burner while maintaining the mixing ratio of the two components exactly as set. .

[0009]

According to the present invention, at least one burner for spraying a vaporized silica glass raw material onto a seed rod to cause a flame hydrolysis reaction to adhere to the seed rod is provided. At least one storage container that stores silica glass raw materials by type, a vapor generation mechanism that vaporizes the liquid raw material in the storage container, and at least one ventilation path that guides the vaporized main component gas to the burner; A second component gas passage connected in the middle of the ventilation path; a main component gas and a second component gas are mixed in a line downstream of a connection portion between the ventilation path and the second component gas path to be mixed with the burner; In the silica glass manufacturing apparatus to be fed, the connection structure between the ventilation path having the minimum flow rate of the main component gas and the second component gas path in the connection section between the ventilation path and the second component gas path. And a structure as can spewing the main component gas toward the central portion of the flow passage cross section of the second component gas.

[0010] If the main component gas having a small flow rate is ejected toward the center of the cross section of the second component gas, and the main component gas is sent to a location where the flow of the second component gas is strong, The gas can be mixed efficiently. Here, such a connection structure is particularly effective at a connection portion where the flow rate of the main component gas is small, but is freely applicable to other connection portions or connection portions of all lines.

In this case, a part of the connection end of the ventilation path for injecting the main component gas is inserted into the large diameter portion of the pipe of the second component gas passage to partially form the double pipe. If the diameter of the flow path is reduced to a small diameter portion on the downstream side of the double pipe structure, the flow path of the outer gas is narrowed, and the inner gas flow is forced to enter, The mixing of the gases is made more efficient.

According to a third aspect of the present invention, the average flow velocity of the mixed gas immediately after the mixing of the main component gas and the second component gas is set to 0.1 / sec.
50 m or more. By setting the average flow velocity to 0.50 m or more in this way, even when the gas flow rate setting value is changed, for example, a stagnant flow area is not formed in the pipe, and the gas can be mixed uniformly.

At this time, as described in claim 4, where the average flow velocity of the mixed gas is set to 0.50 m / sec or more, one of the inner diameters is set.
The use of a pipe having 0 or more pipes can more effectively prevent a stagnant basin.

According to a fifth aspect of the present invention, at least one burner for spraying a vaporized silica glass raw material to a seed rod to cause a flame hydrolysis reaction to adhere thereto, and at least one burner for storing a liquid silica glass raw material for each type. A base storage container, a vapor generation mechanism for vaporizing the liquid raw material in the storage container, at least one ventilation path for guiding the vaporized main component gas to the burner, and a second connection partway through the ventilation path. An apparatus for producing silica glass, comprising a two-component gas passage, wherein a main component gas and a second component gas are mixed and sent to the burner in a line downstream of a connection portion between the ventilation path and the second component gas passage. The pipes of the ventilation passage upstream of the connection, the second component gas passage, and the ventilation passage downstream of the connection are heated by PID-controlled heaters.

As described above, instead of the conventional heater of the on / off control, heating is performed by the heater of the PID control which calculates the rate of change, smoothly calculates the target value from the calculated value, and generates a control signal. As in the control method described above, there is no problem that the volume of the gas expands and contracts when it is turned on and off, and it is possible to prevent the flow rate and the component ratio of the mixed gas from changing.

According to a sixth aspect of the present invention, when the apparatus for producing a silica glass according to any one of the first to fourth aspects is combined with the apparatus for producing a silica glass according to the fifth aspect, gas Can be more efficiently mixed, the component ratio of the mixed gas can be accurately maintained, and the quality of the manufactured product can be stabilized.

[0017]

Embodiments of the present invention will be described with reference to the accompanying drawings. Here, FIG. 1 is a structural example diagram of a silica glass manufacturing apparatus according to the present invention, FIG. 2 is an explanatory view of a connecting structure of a connecting portion between an air passage and a second component gas passage according to the present invention, and FIG. It is explanatory drawing of a connection structure.

The apparatus for producing silica glass according to the present invention comprises:
For example, the present invention is applied to an apparatus for manufacturing a single mode optical fiber preform. This apparatus includes a plurality of chambers Q1, Q2 as shown in FIG.
While rotating the seed rod T in the inside 2, it is pulled up in the axial direction and sprays vaporized silicon tetrachloride (SiCl ₄ ) gas from the core forming burners 1 and 2 and the cladding forming burner 3. By spraying germanium tetrachloride (GeCl ₄ ) gas for controlling the refractive index, silica fine particles and dope fine particles are deposited and deposited in the axial direction of the seed rod T to grow the fiber preform P.

Then, silicon tetrachloride (SiCl ₄ ) gas and germanium tetrachloride (GeCl ₄ ) for each of the burners 1 to 3 are used.
₄ ) Gases include liquid silicon tetrachloride (SiCl ₄ ) and germanium tetrachloride (GeCl ₄ ) stored in the common metal containers 4 and 5 according to their types, and the respective vapor generating mechanisms 6 and 7.
To produce a main component gas, which is distributed and supplied.

That is, a metal container 4 for storing silicon tetrachloride (SiCl ₄ ) and germanium tetrachloride (GeCl ₄ )
₄ ) Each of the chambers Q1 and Q
Ventilation with dispensing line is configured for insufflation of the main component gas toward the 2, line configuration in each chamber Q1 (Q2) is connected to the metallic container 4 of silicon tetrachloride (SiCl ₄₎ From the line 0-1 to the respective burners 1, 2, 3 respectively, the ventilation line 1-1, 2-1 and 3-1
Are provided in a branched manner, and each of these lines 1-1, 2-1 and
3-1 includes each line 1- as a second component gas passage.
2, 2-2 and 3-2 are connected at respective connection portions A, C and D. Incidentally, this second component gas is supplied to the line 1
-2 and 2-2 are Ar gas, and line 3-2 is O ₂ gas.

On the other hand, germanium tetrachloride (GeCl ₄ )
A vent line 1-3 is connected to the metal container 5 for storing the air, and the vent line 1-3 is connected to a vent line 1-4 extending from the connection part A at a connection part B. The connecting portion B and the core forming burner 1 are connected to the ventilation line 1-5.
Connected by The connecting portion C and the core forming burner 2 are connected by a vent line 2-3, and the connecting portion D and the cladding forming burner 3 are connected by a vent line 3-3.
Connected by

A mass flow controller (hereinafter, referred to as a temperature controller) having a temperature controller for controlling the amount of flowing gas is provided in the ventilation line lines 1-1, 2-1 and 3-1 for the silicon tetrachloride (SiCl ₄ ) gas. , MFC.) 8, 9, 10 are provided, and an MFC 11 with a temperature controller is also provided in a gas passage line 1-3 of germanium tetrachloride (GeCl ₄ ) gas. Lines 1-2, 2-2, 3-2
Are provided with MFCs 12, 13, and 14, respectively.

Each line includes a pipe body and an MFC
Various temperature controllers are provided to maintain the temperature at a predetermined temperature.These temperature controllers consist of a temperature detector, a temperature controller, a heater, etc., and calculate the rate of temperature change to smoothly reach the target temperature. The temperature is kept constant by PID control.

That is, the air passage lines 1-1, upstream of the connection portions A, C, D of silicon tetrachloride (SiCl ₄ ) gas.
2-1 and 3-1 and second component gas lines 1-2 and 2-
2 and 3-2 are PIs by the temperature controller 15 (TIC-SiCl ₄ ).
D controlled so that germanium tetrachloride (GeC
l ₄ ) Ventilation line line 1-3 upstream of gas connection B
Are PID controlled by the temperature controller 16 (TIC-GeCl ₄ ). Further, temperature controllers 17, 18, and 19 for PID control are also provided on the ventilation line lines 1-5, 2-3, and 3-3 downstream of the connection portions B, C, and D, respectively. Incidentally, the temperature controller of each line of the conventional apparatus mainly controlled on / off.

Further, all connection structures of the connection portions A, B, C, D are configured as shown in FIG. That is, at the connection points A, C, and D where the silicon tetrachloride (SiCl ₄ ) gas and the second component gas are mixed, the ends of the pipes of the lines 1-2, 2-2, and 3-2 of the second component gas are connected. The connection small diameter portion K of the gas passage line 1-1, 2-1 and 3-1 of the silicon tetrachloride (SiCl ₄ ) gas is inserted into the central portion of the connection large diameter portion H as the connection large diameter portion H. It has a double tube structure so that silicon tetrachloride (SiCl ₄ ) gas can be jetted at a flow rate u1 toward the center of the cross section of the second component gas flowing at a flow rate u2.

At a connection portion B for mixing germanium tetrachloride (GeCl ₄ ) gas with a mixed gas obtained by mixing silicon tetrachloride (SiCl ₄ ) gas and the second component gas, the connection size of the ventilation line 1-4 is increased. A small-diameter portion K of a gas passage line 1-3 of germanium tetrachloride (GeCl ₄ ) gas is inserted into the diameter portion H to form a double pipe structure, which is directed toward the center of the cross-section of the mixed gas flowing at a flow rate u2. Germanium tetrachloride (G
eCl ₄ ) gas can be ejected at a flow rate u1.

On the downstream side of the double pipe structure, there is provided a small diameter portion S in which the diameter of the outer pipe is reduced. The length L of the small diameter portion S is at least 10 times the inner diameter D4 of the small diameter portion S.

In this embodiment, all of the connection parts A to A
Although the connection structure of D is configured as shown in FIG. 2, such a structure is effective in increasing the mixing efficiency particularly in a place where the flow rate of the main component gas is small. Is applied to the connection part of the line in which is minimized.

In the manufacturing apparatus configured as described above,
Silicon tetrachloride (SiCl ₄ ) and germanium tetrachloride (GeCl ₄ ) in metal containers 4 and 5 are vaporized by respective steam generating mechanisms 6 and 7 to generate a main component gas. At this time, since the vaporization rate is proportional to the amount of heating, each of the steam generating mechanisms 6 and 7 can increase or decrease the amount of heating in accordance with a change in the total consumed steam flow rate. Among the plurality of ventilation lines, the pressure is maintained accurately so that the pressure value is at least 0.35 kg / cm ² or more higher than the pressure value of the line having the highest back pressure. And
Each of the MFCs 8 to 11 controls the gas flow using the pressure difference higher than 0.35 kg / cm ² .

The main component gas sent by the pressure difference as described above and the second component gas sent at a predetermined pressure are used for the burner 2 for forming the core and the burner 3 for forming the clad.
After being mixed at the connection portions C and D respectively, each burner 2, 3
Air is sent to Further, the core forming burner 1 is mixed at the connection portion A, further mixed with the dope material at the connection portion B, and sent to the burner 1. In each of these connection parts A to D, as shown in FIG. 2, one side gas to be mixed is blown out toward the strong central portion of the gas flow on the other side and along the flow direction.
Mixing can be performed more efficiently as compared with the conventional cheese union structure as shown in FIG. 3, and the diameter on the downstream side of the double tube structure is reduced to a small diameter portion S, and the length L is changed to the inner diameter D4. Since it is 10 times or more, the flow path of the outer gas is forcibly narrowed and penetrates into the inner gas, so that mixing can be performed more efficiently.

Further, since each gas flowing in the line is heated to an appropriate temperature by a PID-controlled temperature controller provided in each line, problems due to gas condensation in the line are prevented, and In addition, the expansion and contraction of the flow caused by the conventional on / off control are eliminated, and the component ratio of the mixed gas can be appropriately maintained.

The optical characteristics of the product preform can be stabilized by increasing the efficiency of gas mixing and optimizing the component ratio as described above.

[0033]

Next, examples of the present invention and comparative examples will be described. (Example 1) As an apparatus for manufacturing an optical fiber preform, one set of a common evaporator (metal container and steam generating mechanism) was provided, and hot water of 80 ° C was used as a heat source, and the amount of heating was adjusted. , The gas pressure of the main component gas is 0.5
KG so as to be kept at 69 ° C. At this time, the inner diameter of the evaporator was 200 mmφ, the capacity was 10 liters, and two lines of the chambers Q1 and Q2 were connected.
Each burner 1-3 of each chamber Q1, Q2 is 5
0 SCCM, 100 SCCM, 1 SLM, one set of 3 units, each burner 1
Back pressure at ~ 3 was a maximum of 0.1KG.

At this time, the connection structures of the connection portions A, B, C, and D of the line are all as shown in FIG. 2. At this time, the inside diameter of the connection small diameter portion K is D1, and the outside diameter is D2, When the inside diameter of the connection large diameter portion H is D3, the inside diameter of the small diameter portion S is D4, and the length of the small diameter portion S is L, the dimensions are shown in Table 1.

[0035]

[Table 1]

As a result, the flow rates SCCM and flow rates u1 and u2 of the gases before mixing and the flow rates u3 of the gases after mixing at the connection points A to D are as shown in Table 2, and the flow rates u3 of the mixed gases are shown in Table 2.
Were all 0.50 Nm / s or more. Also, product preforms made using the finished core rod are
As shown in Table 4 below, all of the materials passed the specifications and passed.

[0037]

[Table 2]

(Comparative Example 1) On the other hand, connecting portions A to D
FIG. 3 shows a conventional apparatus having a structure shown in FIG.
Table 3 shows the M, the flow rates u1, u2, and the flow rate u3 of the mixed gas.
It is only the clad forming burner 3 that the flow velocity u3 of the mixed gas was 0.50 Nm / s or more, and especially in the line where the flow rate of the main component gas is small, the gas mixing easily proceeds. In particular, when the flow rate set value changes, etc., a stagnant flow area may be formed in the piping, and as a result, the growth of the core rod may be incomplete and adhesion may be poor, or the core rod may be manufactured using a finished core rod. The optical properties of the product preform may change significantly in the longitudinal direction,
As shown in Table 4, the yield was poor.

[0039]

[Table 3]

[0040]

[Table 4]

(Embodiment 2) The temperature controllers 15 to 1 provided in the pipe main body of each line by the apparatus configuration as shown in FIG.
The gas temperature of each line was controlled at a set temperature as shown in Table 5 by PID control using temperature controllers provided in the MFCs 9 and 11 of the main component gas lines. As a result,
As shown in Table 5, the temperature change was ±
Maintained within 2 ° C and the flow rate fluctuation is ± 1%
The product preforms manufactured using the finished core rods were all within the specification as shown in Table 7 below.

[0042]

[Table 5]

(Comparative Example 2) On the other hand, when the temperature was controlled at the same temperature setting using a conventional apparatus for controlling the on / off of the temperature controller of the line, as shown in Table 6, the temperature change was ± 8. ° C, and the flow fluctuations associated therewith also increase greatly. Particularly in a flow of a small flow rate such as germanium tetrachloride (GeCl ₄ ) gas, a significant expansion and contraction occurs in the flow volume every time the on / off control operation is performed in the piping. Occurred.
As a result, at the burner reaction point, the ratio of the gas components changed every moment, and as shown in Table 7, the change in the optical characteristics of the product preform in the longitudinal direction became large, and a decrease in the product yield was recognized.

[0044]

[Table 6]

[0045]

[Table 7]

From the above, the effectiveness of the present invention was confirmed.

The present invention is not limited to the above embodiment. The above embodiment is an exemplification, and has substantially the same configuration as the technical idea described in the scope of the claims of the present invention. It is included in the technical scope of the invention.

For example, the number of the burners 1 to 3 is optional, and the type of the second component gas is optional. Also,
The structure of the connecting portion may not be particularly provided at a place where the flow rate of the main component gas is large.

[0049]

As described above, the apparatus for producing silica glass according to the present invention is an apparatus for mixing a vaporized main component gas and a second component gas and sending the mixture to a burner. The main component gas can be ejected toward the center of the cross section of the flow path of the second component gas as a connection structure of a predetermined connection portion of the connection portions of the second component gas passage and the second component gas passage. Can be mixed. At this time, if a part of the connecting portion has a double pipe structure, and the flow path diameter is reduced to a small diameter portion on the downstream side of the double pipe structure, the flow path of the outer gas is narrowed and the inner gas is forcibly forced. Of the gas flow into the inside of the gas flow can be mixed more efficiently.

If the average flow velocity of the mixed gas immediately after the main component gas and the second component gas are mixed is equal to or higher than a predetermined speed, even when the gas flow rate is changed, for example, the stagnant flow region is formed in the pipe. Is not formed, and the gas mixture can be made uniform. Further, if a pipe having a predetermined length of pipe is used at a location where the average flow velocity of the mixed gas is equal to or higher than a predetermined speed, prevention of a stagnant flow area can be achieved more efficiently.

Further, the air passage upstream of the connection portion is connected to the second air passage.
Heating the component gas passages and each pipe of the ventilation path downstream of the connection portion with a PID control heater eliminates the problem that the volume of the gas flow expands and contracts during on / off control as in the related art. Can be prevented from changing. If the connection structure of the connection part and the PID temperature control of the line are combined, the gas can be efficiently mixed, the component ratio can be accurately maintained, and the quality of the manufactured product can be improved. Can be stabilized.

[Brief description of the drawings]

FIG. 1 is a structural example diagram of an apparatus for producing silica glass according to the present invention.

FIG. 2 is an explanatory diagram of a connection structure such as a connection portion between an air passage and a second component gas passage according to the present invention.

FIG. 3 is an explanatory diagram of a conventional connection structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Burner for core formation, 2 ... Burner for core formation, 3 ...
Burner for forming cladding, 4 ... Metal container, 5 ... Metal container, 6 ... Steam generating mechanism, 7 ... Steam generating mechanism, 8 ...
Mass flow controller (MFC), 9 ... MFC, 10 ... M
FC, 11 ... MFC, 12 ... MFC, 13 ... MF
C, 14: MFC, 15: temperature controller, 16: temperature controller,
17: Temperature controller, 18: Temperature controller, 19: Temperature controller, A ...
Connection part, B ... Connection part, C ... Connection part, D ... Connection part,
H: Connection large diameter part, K: Connection small diameter part, S: Small diameter part,
T: seed rod, P: fiber preform, Q1: chamber, Q
2 ... chamber.

Continued on the front page (72) Inventor Hideo Hirasawa 2-13-1 Isobe, Annaka-shi, Gunma F-term in Shin-Etsu Kagaku Kogyo Co., Ltd. Precision Functional Materials Laboratory 4G014 AH12 4G021 EB06

Claims (6)

[Claims] At least one burner for spraying a vaporized silica glass raw material onto a seed rod to cause a flame hydrolysis reaction to adhere thereto, and at least one storage container for storing liquid silica glass raw material by type A vapor generation mechanism for vaporizing the liquid raw material in the storage container, at least one ventilation path for guiding the vaporized main component gas to the burner, and a second component gas passage connected in the middle of the ventilation path An apparatus for producing silica glass, wherein a main component gas and a second component gas are mixed and sent to the burner in a line downstream of a connection portion between the ventilation path and the second component gas passage, The connection structure between the ventilation path and the second component gas passage, in which the flow rate of the main component gas is at a minimum flow rate, in the connection portion between the ventilation path and the second component gas passage, is a central portion of the cross section of the second component gas flow path To An apparatus for producing silica glass, which has a structure capable of ejecting a main component gas toward the apparatus. 2. The silica glass manufacturing apparatus according to claim 1, wherein a part of a connection end of an air passage for injecting the main component gas is inserted into a large diameter portion of a pipe of the second component gas passage. An apparatus for producing silica glass, characterized in that the flow path diameter is reduced to a small diameter portion downstream of the double pipe structure. 3. The silica glass manufacturing apparatus according to claim 1, wherein an average flow velocity of the mixed gas immediately after the mixing of the main component gas and the second component gas is 0.5 / sec.
An apparatus for producing silica glass, wherein the length is 0 m or more. 4. The apparatus for producing silica glass according to claim 3, wherein the average flow rate of the mixed gas is 0.50 m / sec.
An apparatus for producing silica glass, wherein a pipe having a pipe line having a diameter of 10 times or more is used in the above-mentioned location. 5. At least one burner for spraying a vaporized silica glass raw material onto a seed rod to cause a flame hydrolysis reaction to adhere thereto, and at least one storage container for storing liquid silica glass raw material by type. A vapor generation mechanism for vaporizing the liquid raw material in the storage container, at least one ventilation path for guiding the vaporized main component gas to the burner, and a second component gas passage connected in the middle of the ventilation path An apparatus for producing silica glass, wherein a main component gas and a second component gas are mixed and sent to the burner in a line downstream of a connection portion between the ventilation path and the second component gas passage, Each pipe of the ventilation path upstream of the connection, the second component gas passage, and the ventilation path downstream of the connection is
An apparatus for producing silica glass, wherein the apparatus is heated by an ID-controlled heater. 6. A method for producing silica glass, comprising combining the apparatus for producing silica glass according to claim 1 with the apparatus for producing silica glass according to claim 5. apparatus.