JP6926951B2 - Glass base material manufacturing equipment and manufacturing method - Google Patents

Description

The present invention relates to a glass base material manufacturing apparatus and a manufacturing method.

Patent Document 1 describes a configuration in which the differential pressure between the pressure inside the reaction vessel and the pressure outside the vessel is detected by a precision microdifference pressure gauge in the description of the prior art.
Patent Document 2 describes a configuration in which the pressure in the exhaust pipe is measured with a pressure gauge.

Japanese Unexamined Patent Publication No. 9-40439 International Publication No. 2002/1072729 Pamphlet

When the pressure inside the reaction vessel or the exhaust pipe is measured with a pressure gauge during the production of the glass base material, the pressure gauge may be corroded by the corrosive gas generated in the reaction vessel. Further, for example, glass fine particles that have not been deposited on the glass base material may be suspended in the reaction vessel or the exhaust pipe. For this reason, the glass fine particles may accumulate in the pipe provided with the pressure gauge and clog the pipe, making it impossible to accurately measure the pressure in the reaction vessel or the exhaust pipe.

According to the present invention, when the pressure inside the reaction vessel or the exhaust pipe is measured with a pressure gauge during the production of the glass base material, it is possible to suppress corrosion of the pressure gauge and clogging of the pipe to which the pressure gauge is connected. An object of the present invention is to provide a base material manufacturing apparatus and a manufacturing method.

The glass base material manufacturing apparatus according to one aspect of the present invention is a glass base material manufacturing apparatus provided with an exhaust pipe for discharging gas in the reaction vessel and a pressure gauge for measuring the pressure in the exhaust pipe. And
The pressure gauge
It is connected to the exhaust pipe by piping and
In the pipe, a non-corrosive gas supply unit is connected between the pressure gauge and the exhaust pipe.
The non-corrosive gas supply unit
The non-corrosive gas is configured to flow inside the pipe from the pressure gauge side to the exhaust pipe side.

The glass base material manufacturing apparatus according to another aspect of the present invention is a glass base material manufacturing apparatus provided with a pressure gauge for measuring the pressure in the reaction vessel.
The pressure gauge
It is connected to the reaction vessel by piping and
In the pipe, a non-corrosive gas supply unit is connected between the pressure gauge and the reaction vessel.
The non-corrosive gas supply unit
The non-corrosive gas is configured to flow inside the pipe from the pressure gauge side to the reaction vessel side.

The method for producing a glass base material according to one aspect of the present invention is a method for producing a glass base material for measuring the pressure in the exhaust pipe with a pressure gauge provided in the exhaust pipe for discharging the gas in the reaction vessel. There,
The pressure gauge is connected to the exhaust pipe by a pipe.
The pressure is measured in a state where the non-corrosive gas is flowing inside the pipe from the pressure gauge side to the exhaust pipe side.

The method for producing a glass base material according to another aspect of the present invention is a method for producing a glass base material for measuring the pressure in the reaction vessel with a pressure gauge provided in the reaction vessel.
The pressure gauge is connected to the reaction vessel by a pipe.
The pressure is measured in a state where the non-corrosive gas is flowing inside the pipe from the pressure gauge side to the reaction vessel side.

According to the glass base material manufacturing apparatus and manufacturing method of the above invention, when the pressure in the reaction vessel or the exhaust pipe is measured by the pressure gauge at the time of manufacturing the glass base material, the pressure gauge is corroded or the pressure gauge is connected. It is possible to prevent clogging of the installed pipe.

It is a figure which shows an example of the manufacturing apparatus of the glass base material which concerns on this embodiment. It is a figure which shows another example of the manufacturing apparatus of the glass base material which concerns on this embodiment. It is a graph which shows the relationship between the pressure measurement value when gas is supplied to a pipe, and the pressure measurement value when gas is not supplied. It is a graph which shows an example of the fluctuation of the pressure in the exhaust pipe at the time of manufacturing the glass base material by the manufacturing method of the glass base material which concerns on this embodiment. It is a graph which shows an example of the fluctuation of the pressure in the exhaust pipe at the time of manufacturing a glass base material by the conventional manufacturing method of a glass base material.

(Explanation of Embodiments of the Present Invention)
First, embodiments of the present invention will be listed and described.
The glass base material manufacturing apparatus according to one aspect of the present invention is
(1) A glass base material manufacturing apparatus provided with a pressure gauge for measuring the pressure in the exhaust pipe in the exhaust pipe for discharging the gas in the reaction vessel.
The pressure gauge
It is connected to the exhaust pipe by piping and
In the pipe, a non-corrosive gas supply unit is connected between the pressure gauge and the exhaust pipe.
The non-corrosive gas supply unit
The non-corrosive gas is configured to flow inside the pipe from the pressure gauge side to the exhaust pipe side.

Further, the apparatus for producing a glass base material according to another aspect of the present invention is
(2) A glass base material manufacturing apparatus equipped with a pressure gauge for measuring the pressure in the reaction vessel.
The pressure gauge
It is connected to the reaction vessel by piping and
In the pipe, a non-corrosive gas supply unit is connected between the pressure gauge and the reaction vessel.
The non-corrosive gas supply unit
The non-corrosive gas is configured to flow inside the pipe from the pressure gauge side to the reaction vessel side.

According to the configuration of (1) or (2) above, the non-corrosive gas supply unit causes the non-corrosive gas to flow inside the pipe to which the pressure gauge is connected at the time of manufacturing the glass base material. Corrosion of the meter and clogging of the piping provided with the pressure gauge can be suppressed.

(3) The non-corrosive gas supply unit is an opening provided in the pipe.
The opening may be capable of introducing outside air as the non-corrosive gas.
According to the above configuration, the non-corrosive gas supply unit can be configured with a simple configuration.

(4) The non-corrosive gas supply unit may be able to control the flow rate of the non-corrosive gas to be constant.
According to the above configuration, since the flow rate of the non-corrosive gas flowing through the pipe to which the pressure gauge is connected is constant, the amount of change in the measured value of the pressure gauge can be reduced.

(5) The measured value of the pressure measured when the non-corrosive gas is flowing in the pipe and the measured value of the pressure measured when the non-corrosive gas is not flowing in the pipe. Based on the relationship
A conversion device for estimating the pressure in the reaction vessel from the measured value measured using the pressure gauge while the non-corrosive gas is flowing in the pipe may be provided.
According to the above configuration, the actual pressure in the reaction vessel can be estimated by the conversion device from the measured value measured in the state where the non-corrosive gas is flowing in the pipe to which the pressure gauge is connected. can.

The method for producing a glass base material according to one aspect of the present invention is as follows.
(6) A method for manufacturing a glass base material for measuring the pressure in the exhaust pipe with a pressure gauge provided in the exhaust pipe for discharging the gas in the reaction vessel.
The pressure gauge is connected to the exhaust pipe by a pipe.
The pressure is measured in a state where the non-corrosive gas is flowing inside the pipe from the pressure gauge side to the exhaust pipe side.

Further, the method for producing a glass base material according to another aspect of the present invention is described.
(7) A method for producing a glass base material for measuring the pressure inside the reaction vessel with a pressure gauge provided in the reaction vessel.
The pressure gauge is connected to the reaction vessel by a pipe.
The pressure is measured in a state where the non-corrosive gas is flowing inside the pipe from the pressure gauge side to the reaction vessel side.

According to the manufacturing method (6) or (7) above, when the glass base material is manufactured, the non-corrosive gas is passed through the pipe to which the pressure gauge is connected, so that the pressure gauge is corroded and the pressure gauge is damaged. It is possible to suppress the clogging of the connected pipes.

(8) The non-corrosive gas is outside air and
By providing an opening in the pipe and sucking the outside air through the opening, the pressure may be measured in a state where the outside air is flowing inside the pipe.
According to the above method, outside air, which is a non-corrosive gas, can flow into the inside of the pipe in which the pressure gauge is arranged with a simple structure.

(9) The pressure may be measured with a constant flow rate of non-corrosive gas flowing inside the pipe.
According to the above method, since the flow rate of the non-corrosive gas flowing through the pipe to which the pressure gauge is connected is constant, the amount of change in the measured value of the pressure gauge can be reduced.

(10) Based on the relationship between the measured value measured when the non-corrosive gas is flowing in the pipe and the measured value measured when the non-corrosive gas is not flowing in the pipe. hand,
A measurement may be performed using the pressure gauge in a state where the non-corrosive gas is flowing in the pipe, and the pressure in the reaction vessel may be estimated from the measured value obtained by the measurement.
According to the above method, the actual pressure in the reaction vessel is estimated from the measured value measured using the pressure gauge while the non-corrosive gas is flowing in the pipe to which the pressure gauge is connected. Can be done.

(Details of Embodiments of the present invention)
Specific examples of the glass base material manufacturing apparatus and manufacturing method according to the embodiment of the present invention will be described below with reference to the drawings.
It should be noted that the present invention is not limited to these examples, and is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

FIG. 1 is a schematic configuration diagram showing an apparatus for producing a porous glass base material for an optical fiber as an example of an apparatus for producing a glass base material. As shown in FIG. 1, the apparatus 1 for producing a porous glass base material for optical fibers processes the reaction vessel 2, the exhaust pipe 3 for exhausting the gas in the reaction vessel 2, and the exhaust gas exhausted from the reaction vessel 2. It is provided with an exhaust gas processing unit 4 for processing.

The reaction vessel 2 is a vessel in which the starting rod 21 is housed so as to be able to move up and down from above, and glass fine particles are deposited on the starting rod 21 in the inner space. The reaction vessel 2 is made of a material that is less likely to be corroded by hydrogen chloride gas or the like even under high temperature environmental conditions when the glass base material 10 is formed, for example, silicon dioxide, silicon carbide, nickel, nickel alloy or the like.

The reaction vessel 2 is provided with a burner 22 that produces fine glass particles. The burner 22 has a plurality of ports for blowing out gas, and blows out glass raw material gas such as silicon tetrachloride, oxygen and hydrogen from the ports, and hydrolyzes the glass raw material in an acid hydrogen flame to cause glass. Produces fine particles. The burner 22 is arranged toward the starting rod 21 so as to deposit the generated glass fine particles on the starting rod 21.

Further, the reaction vessel 2 is provided with an exhaust port 23 for discharging exhaust gas. An exhaust pipe 3 is connected to the exhaust port 23, and internal exhaust gas containing excess glass fine particles not deposited on the starting rod 21 is sent out from the exhaust port 23 to the exhaust pipe 3.

The exhaust pipe 3 is provided with a pressure gauge 31 capable of measuring the pressure in the inner space (inside the exhaust pipe 3) in the middle of the pipe line. The pressure in the exhaust pipe 3 correlates with the pressure in the reaction vessel 2. Therefore, by measuring the pressure change in the exhaust pipe 3, it is possible to detect the pressure change in the reaction vessel 2 at the time of manufacturing the glass base material 10. The exhaust pipe 3 is made of, for example, nickel, a nickel alloy, or the like. The diameter of the exhaust pipe 3 is, for example, 50 mm to 300 mm.

The pressure gauge 31 is connected to a pipe 32 provided in communication with the exhaust pipe 3. Therefore, the pressure in the exhaust pipe 3 communicating with the pipe 32 can be measured. The diameter of the pipe 32 is, for example, 3 mm to 7 mm.

The pipe 32 is provided with a gas introduction pipe 33 that is provided so as to communicate with the pipe 32 so as to branch from the middle of the pipe line. The gas introduction pipe 33 is provided so as to branch from a position in the pipe 32 where the pressure gauge 31 is provided and a position where the exhaust pipe 3 is provided.

The gas introduction pipe 33 is provided with a non-corrosive gas supply unit 34 at the end thereof for introducing a non-corrosive gas. The non-corrosive gas introduced from the non-corrosive gas supply unit 34 is made to flow from the gas introduction pipe 33 to the inside of the pipe 32. The non-corrosive gas flows from the side of the pipe 32 to which the pressure gauge is connected to the side of the pipe 32 to which the exhaust pipe 3 is communicated (in the direction of arrow A).

The non-corrosive gas supply unit 34 of this example is formed as an opening 34A in which the end of the gas introduction pipe 33 is open. The opening 34A is configured so that outside air (air) is introduced as a non-corrosive gas flowing into the inside of the pipe 32.

An outside air adjusting valve 35 for adjusting the amount of outside air introduced is provided in the middle of the gas introduction pipe 33. An introduction amount control unit 37 capable of adjusting the opening and closing of the valve is connected to the outside air adjusting valve 35.

Further, the gas introduction pipe 33 is provided with a flow meter 36 for measuring the flow rate of the outside air introduced into the gas introduction pipe 33 on the downstream side (the side close to the pipe 32) of the outside air adjusting valve 35. The introduction amount control unit 37 adjusts the opening and closing of the outside air adjusting valve 35 according to the flow rate value measured by the flow meter 36, and controls so that the flow rate of the outside air flowing through the pipe 32 becomes constant.

In the non-corrosive gas supply unit 34, instead of the opening 34A, for example, a gas supply pipe for supplying a non-corrosive gas (for example, nitrogen gas) is connected to the introduction pipe 33 to supply the non-corrosive gas. It may be a gas supply device to be supplied. With such a gas supply device, a non-corrosive gas (for example, nitrogen gas) may be introduced into the introduction pipe 33 at a constant flow rate.

Further, the pressure gauge 31 is connected to an exhaust amount control unit 38 for controlling the amount of exhaust gas exhausted from the exhaust pipe 3. The pressure value measured by the pressure gauge 31 is sent to the displacement control unit 38.

The exhaust pipe 3 is provided with an exhaust amount adjusting valve 39 in the middle of the pipe line. The displacement adjusting valve 39 of this example is arranged on the downstream side (closer to the exhaust gas processing unit 4) of the exhaust pipe 3 than the position where the pressure gauge 31 is provided. A displacement control unit 38 is connected to the displacement adjustment valve 39, and the opening / closing operation of the displacement adjustment valve 39 is adjusted by the displacement control unit 38. The pressure inside the reaction vessel 2 is measured by the pressure gauge 31, and the opening and closing of the displacement adjusting valve 39 is controlled by the displacement control unit 38 as the pressure value fluctuates, so that the pressure inside the reaction vessel 2 is kept constant. ing.

The displacement control unit 38 has a conversion device 38a that estimates the pressure in the reaction vessel 2 based on the pressure value in the pipe 32 measured by the pressure gauge 31. The conversion device 38a has a pressure value in the pipe 32 measured in a state where the outside air is flowing in the pipe 32 and a pressure value in the pipe 32 measured in a state where the outside air is not flowing in the pipe 32. A conversion table in which and is associated with each other is stored. The conversion device 38a measures the pressure value in the pipe 32 while the outside air is flowing in the pipe 32, and estimates the pressure in the reaction vessel 2 with reference to the conversion table.

The exhaust gas processing unit 4 performs processing for removing glass fine particles, harmful acid gas, and the like from the exhaust gas exhausted through the exhaust pipe 3. The exhaust gas treatment unit 4 includes, for example, a cooling tower that cools and controls the humidity of the exhaust gas, a dust collector that collects glass fine particles in the exhaust gas, an exhaust fan that sucks the exhaust gas, and chlorine and chloride in the exhaust gas. It has a gas adsorption device that adsorbs acid gas such as hydrogen (not shown).

For example, by rotating the impeller by the motor of the exhaust fan, the exhaust gas in the exhaust pipe 3 is sucked into the exhaust gas processing unit 4. Due to this suction, the pressure in the exhaust pipe 3 and the pipe 32 connected to the exhaust gas processing unit 4 becomes a negative pressure, so that the outside air introduced from the opening 34A is directed into the pipe 32 (pointing to the arrow A). Negative pressure is sucked.

In this example, the case where the pipe 32 to which the pressure gauge 31 is connected is provided in communication with the exhaust pipe 3 has been described. For example, as shown in FIG. 2, the pipe 32 is provided in communication with the reaction vessel 2. May be good. FIG. 2 is a schematic configuration diagram showing a device 1A for producing a porous glass base material for an optical fiber as another example of the device for producing a glass base material. In the case of the example shown in FIG. 2, the configuration for introducing the non-corrosive gas into the pipe may be the same as the configuration in which the pipe 32 communicates with the exhaust pipe 3.

FIG. 3 shows a pressure value P1 (vertical axis) in the pipe 32 measured in a state where the outside air is flowing in the pipe 32, and a inside of the pipe 32 measured in a state where the outside air is not flowing in the pipe 32. It is a graph which shows the relationship with the pressure value P2 (horizontal axis) of. Both P1 and P2 have a negative pressure, but the absolute values are shown thereafter including FIG. As shown in FIG. 3, the pressure value P1 measured in the state where the outside air is flowing is more than the pressure value P2 measured in the state where the outside air is not flowing due to the pressure loss when flowing in the pipe 32. Is also a small value. The correspondence between the pressure value P1 and the pressure value P2 is stored as a conversion table in the conversion device 38a of the displacement control unit 38. Therefore, by measuring the pressure value P1 in the pipe 32 in the state where the outside air is flowing in the pipe 32 with the pressure gauge 31, the correspondence relationship between the pressure value P1 and the pressure value P2 (for example, the above conversion table). ) Can be used to estimate the actual pressure inside the reaction vessel 2.

Next, a method of manufacturing the porous glass base material for optical fibers by the apparatus 1 for manufacturing the porous glass base material for optical fibers having the above configuration will be described.
First, the starting rod 21 suspended close to the burner 22 in the reaction vessel 2 is rotated about an axis. An oxyhydrogen flame is generated from the burner 22 toward the rotating starting rod 21. In an oxyhydrogen flame, glass fine particles are produced by a hydrolysis reaction. The generated glass fine particles adhere to the starting rod 21 and gradually accumulate around the starting rod 21. By gradually pulling up the starting rod 21 according to the state of deposition of the glass fine particles while rotating it about the axis, the porous glass deposits on which the glass fine particles are deposited grow in the axial direction of the starting rod 21. The desired glass base material 10 can be produced.

During the production of the glass base material 10, exhaust gas containing chlorine, hydrogen chloride, undeposited glass fine particles, and the like is generated in the reaction vessel 2. The generated exhaust gas is discharged from the exhaust port 23 of the reaction vessel 2 toward the exhaust pipe 3.

Further, at the time of manufacturing the glass base material 10, the pressure in the reaction vessel 2 is monitored in order to keep the pressure in the reaction vessel 2 constant. The pressure inside the reaction vessel 2 is monitored by measuring the pressure inside the pipe 32 provided in communication with the exhaust pipe 3 with a pressure gauge 31. When measuring the pressure in the pipe 32, in the pipe 32, from the side to which the pressure gauge 31 is connected to the side to which the exhaust pipe 3 is connected, a non-corrosive gas is used inside the pipe 32. A certain outside air is washed away.

The outside air is introduced from the opening 34A of the gas introduction pipe 33 provided so as to branch from the pipe 32. The outside air introduced from the opening 34A is sucked by the exhaust gas processing unit 4, and as shown by an arrow A (see FIG. 1), the exhaust pipe of the pipe 32 is connected to the pressure gauge 31 of the pipe 32. 3 flows toward the connected side. The flow rate of the outside air flowing through the pipe 32 is controlled to be a constant flow rate by adjusting the opening and closing of the outside air adjusting valve 35 by the introduction amount control unit 37. The pressure inside the pipe 32 is measured by the pressure gauge 31 in a state where a constant flow rate of outside air is flowing through the pipe 32.

The exhaust pipe 3 is provided with an exhaust amount adjusting valve 39 for adjusting the exhaust amount of the exhaust gas, and the exhaust amount control unit 38 controls the opening and closing of the exhaust amount adjusting valve 39 to exhaust the exhaust gas. The amount is adjusted.

In the conversion device 38a provided in the displacement control unit 38, the pressure value in the pipe 32 measured in advance with the outside air flowing in the pipe 32 and the outside air not flowing in the pipe 32. A conversion table in which the pressure values in the pipe 32 measured in the state are associated with each other is stored.

The pressure value P1 in the pipe 32 is measured by the pressure gauge 31 in a state where a constant flow rate of outside air is flowing in the pipe 32, and the measured pressure value P1 is transmitted to the conversion device 38a. The conversion device 38a converts the transmitted pressure value P1 in the pipe 32 into the pressure value P2 in the pipe 32 measured in a state where the outside air is not flowing in the pipe 32 with reference to the conversion table. Based on the converted pressure value P2, the displacement control unit 38 controls the opening and closing of the displacement adjustment valve 39, and the pressure value P2 is kept constant. Since the pressure in the reaction vessel 2 has a correlation with the pressure value P2, the pressure in the reaction vessel 2 is also kept constant by keeping the pressure value P2 constant.
The porous glass base material for optical fibers produced by the above method is sintered in a heating furnace to form a glass base material for optical fibers, and is sequentially heated and melted from the end to be drawn to form an optical fiber.
Although the manufacturing apparatus and manufacturing method of the porous glass base material for optical fibers have been described as an example, the present invention is also applied to the manufacturing equipment and manufacturing method of the glass base material for manufacturing synthetic quartz glass. Can be done.

(Experimental example)
In this experimental example, the glass base material was continuously manufactured by the manufacturing apparatus 1 of the porous glass base material for optical fiber and the above-mentioned manufacturing method according to the present embodiment. The fluctuation of the pressure in the exhaust pipe 3 measured at the time of manufacturing is shown in the graph of FIG. FIG. 4 shows fluctuations for three glass base materials manufactured continuously. Further, for comparison, a conventional example of the measured fluctuation of the pressure in the exhaust pipe in which the glass base material is continuously manufactured by the conventional manufacturing apparatus for the porous glass base material for optical fiber is shown in the graph of FIG. .. FIG. 5 shows fluctuations for three glass base materials manufactured continuously.
As shown in FIG. 4, it can be seen that the fluctuation of the pressure in the exhaust pipe 3, that is, the fluctuation of the pressure in the reaction vessel 2 is smaller in the present embodiment than in the conventional example of FIG.

In the above manufacturing method, the pressure in the reaction vessel 2 is monitored by measuring the pressure in the pipe 32 provided in communication with the exhaust pipe 3, but for example, the reaction vessel 2 has the same configuration as the pipe. The pressure inside the reaction vessel 2 may be monitored by measuring the pressure inside the pipe.

According to the manufacturing apparatus 1 and manufacturing method for the porous glass base material for optical fibers as described above, the exhaust pipe 3 is connected from the side to which the pressure gauge 31 is connected in the pipe 32 at the time of manufacturing the glass base material. The outside air, which is a non-corrosive gas, is flowing toward the side of the glass. Therefore, the flow of the outside air can prevent the exhaust gas containing chlorine, hydrogen chloride, undeposited glass fine particles, and the like generated in the reaction vessel 2 from flowing toward the pressure gauge 31 in the pipe 32. can. As a result, corrosion of the pressure gauge 31 due to exhaust gas can be suppressed, and clogging of the pipe 32 due to glass fine particles can be suppressed. Therefore, the pressure in the reaction vessel 2 can be kept constant, and the deposited state of the glass fine particles can be stabilized.

Further, the non-corrosive gas supply unit 34 for introducing the non-corrosive gas into the pipe 32 can be configured by the opening 34A formed in the gas introduction pipe 33. Therefore, the non-corrosive gas supply unit 34 can have a simple structure, and the outside air can be introduced as the non-corrosive gas, so that the manufacturing cost can be suppressed.

Further, since the flow rate of the outside air flowing through the pipe 32 is controlled to be constant, it is possible to suppress fluctuations in the pressure value measured by the pressure gauge 31 connected to the pipe 32. As a result, the pressure in the reaction vessel 2 adjusted based on the measured value of the pressure gauge 31 can be kept constant, and the accumulated state of the glass fine particles can be stabilized.

Further, the pressure value in the pipe 32 measured when the outside air is flowing in the pipe 32 is associated with the pressure value in the pipe 32 measured when the outside air is not flowing in the pipe 32. The conversion table is provided, and based on this conversion table, the pressure value in the pipe 32 measured in a state where the outside air is not flowing in the pipe 32 is converted into the pressure value in the pipe 32, and the pressure in the reaction vessel 2 is estimated. .. Therefore, since the pressure inside the reaction vessel 2 can be accurately detected, the pressure inside the reaction vessel 2 can be kept constant, and the deposited state of the glass fine particles can be stabilized.

Further, since the pressure value in the reaction vessel 2 can be measured accurately and stably, for example, when the estimated pressure in the reaction vessel 2 exceeds a predetermined threshold value, the reaction vessel 2 is appropriately operated. Can be stopped.

In the above embodiment, as an example of the glass base material manufacturing apparatus, an apparatus for producing a porous glass base material by depositing glass fine particles on a starting rod has been described, but the glass base material manufacturing apparatus is described. For example, it may be an apparatus for dehydrating or sintering a porous glass base material.

Although the present invention 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 the invention. Further, the number, position, shape and the like of the constituent members described above are not limited to the above-described embodiment, and can be changed to a number, position, shape and the like suitable for carrying out the present invention.

1, 1A: Manufacturing equipment for porous glass base material for optical fiber 2: Reaction vessel 3: Exhaust pipe 4: Exhaust gas treatment unit 10: Glass base material 23: Exhaust port 31: Pressure gauge 32: Piping 33: Gas introduction pipe 34: Non-corrosive gas supply unit 34A: Opening (non-corrosive gas supply unit)
35: Outside air adjustment valve 36: Flow meter 37: Introductory amount control unit 38: Exhaust amount control unit 38a: Conversion device 39: Exhaust amount adjustment valve

Claims (8)

A glass base material manufacturing apparatus provided with a pressure gauge for measuring the pressure in the exhaust pipe in the exhaust pipe for discharging the gas in the reaction vessel.
The pressure gauge
It is connected to the exhaust pipe by piping and
In the pipe, a non-corrosive gas supply unit is connected between the pressure gauge and the exhaust pipe.
The non-corrosive gas supply unit
The non-corrosive gas is configured to flow inside the pipe from the pressure gauge side to the exhaust pipe side .
Based on the relationship between the measured value of the pressure measured when the non-corrosive gas is flowing in the pipe and the measured value of the pressure measured when the non-corrosive gas is not flowing in the pipe. hand,
It has a conversion device that estimates the pressure in the reaction vessel from the measured value measured by the pressure gauge while the non-corrosive gas is flowing in the pipe .
Glass base material manufacturing equipment. A glass base material manufacturing device equipped with a pressure gauge for measuring the pressure inside the reaction vessel.
The pressure gauge
It is connected to the reaction vessel by piping and
In the pipe, a non-corrosive gas supply unit is connected between the pressure gauge and the reaction vessel.
The non-corrosive gas supply unit
The non-corrosive gas is configured to flow inside the pipe from the pressure gauge side to the reaction vessel side .
Based on the relationship between the measured value of the pressure measured when the non-corrosive gas is flowing in the pipe and the measured value of the pressure measured when the non-corrosive gas is not flowing in the pipe. hand,
It has a conversion device that estimates the pressure in the reaction vessel from the measured value measured by the pressure gauge while the non-corrosive gas is flowing in the pipe .
Glass base material manufacturing equipment. The non-corrosive gas supply unit is an opening provided in the pipe.
The opening can introduce outside air as the non-corrosive gas.
The glass base material manufacturing apparatus according to claim 1 or 2. The non-corrosive gas supply unit can control the flow rate of the non-corrosive gas to be constant.
The apparatus for manufacturing a glass base material according to any one of claims 1 to 3. A method for producing a glass base material for measuring the pressure in the exhaust pipe with a pressure gauge provided in the exhaust pipe for discharging the gas in the reaction vessel.
The pressure gauge is connected to the exhaust pipe by a pipe.
Toward the exhaust pipe side from the pressure gauge side, it has rows of pressure measured when the non-corrosive gas is flowing through the inside of the pipe,
Based on the relationship between the measured value measured when the non-corrosive gas is flowing in the pipe and the measured value measured when the non-corrosive gas is not flowing in the pipe.
A measurement is performed using the pressure gauge in a state where the non-corrosive gas is flowing in the pipe, and the pressure in the reaction vessel is estimated from the measured value obtained by the measurement .
Manufacturing method of glass base material. A method for producing a glass base material for measuring the pressure inside the reaction vessel with a pressure gauge provided in the reaction vessel.
The pressure gauge is connected to the reaction vessel by a pipe.
Toward the reaction container side from the pressure gauge side, it has rows of pressure measured when the non-corrosive gas is flowing through the inside of the pipe,
Based on the relationship between the measured value measured when the non-corrosive gas is flowing in the pipe and the measured value measured when the non-corrosive gas is not flowing in the pipe.
A measurement is performed using the pressure gauge in a state where the non-corrosive gas is flowing in the pipe, and the pressure in the reaction vessel is estimated from the measured value obtained by the measurement .
Manufacturing method of glass base material. The non-corrosive gas is outside air and
By providing an opening in the pipe and sucking the outside air through the opening, the pressure is measured in a state where the outside air is flowing inside the pipe.
The method for producing a glass base material according to claim 5 or 6. Pressure is measured with a constant flow rate of non-corrosive gas flowing inside the pipe.
The method for producing a glass base material according to any one of claims 5 to 7.

Images