Method and apparatus for manufacturing glass particle deposit

Abstract

To provide a method and apparatus for manufacturing a glass particle deposit, capable of improving the operation rate of the entire manufacturing facility.SOLUTION: A method for manufacturing a glass particle deposit comprises: a deposition step of depositing glass fine particles generated by hydrolysis reaction due to burner flame on a target in a reaction vessel; and an extraction step of extracting a glass particle deposit manufactured by the deposition step from the reaction vessel to carry the glass particle deposit to a clean room. Air passing through a clean room filter for removing fine particles in the air is introduced into the clean room; and in the deposition step, the air passing through the reaction vessel filter from a space different from that of the clean room is introduced into the reaction vessel.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method and an apparatus for producing a soot glass deposit body. [Background technology]

[0002] Patent Document 1 discloses a method for producing a soot glass deposit body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-166992 A Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses a method for producing a soot glass deposit body in which clean air is supplied to an external vessel covering a reaction vessel in which soot glass is deposited on a target. Supplying clean air to the external vessel makes it possible to prevent foreign matter from adhering to the soot glass deposit body.

[0005] In the manufacturing apparatus for a soot glass deposit body, clean air may be introduced from a clean room. In the clean room, the degree of cleanliness is adjusted by a filter. In addition, a plurality of reaction vessels may be connected to a common clean room.

[0006] The filters used to introduce air into the clean room are replaced as needed, and at that time, all reaction vessels for glass soot deposits connected to the clean room are stopped from operating.

[0007] The present disclosure provides a method and an apparatus for producing a soot glass deposit body that improve the operating rate of the entire production facility. [Means for solving the problem]

[0008] A method for producing a soot glass deposit body according to one embodiment of the present disclosure includes the steps of: a deposition step of depositing glass particles generated by a hydrolysis reaction caused by a flame of a burner on a target in a reaction vessel; a removing step of removing the soot glass deposit produced by the depositing step from the reaction vessel and transporting it to a clean room; A method for producing a soot glass deposit body, comprising: introducing air into the clean room through a clean room filter that removes particulates from the air; In the deposition step, air is introduced into the reaction vessel through a reaction vessel filter from a space different from the clean room.

[0009] An apparatus for manufacturing a soot glass deposit body according to one aspect of the present disclosure includes: a reaction vessel for depositing glass particles generated by a hydrolysis reaction caused by a flame of a burner on a target therein to produce a glass particle deposit body; a conveyor for conveying the produced soot glass deposit body to a clean room whose cleanliness is adjusted; An apparatus for manufacturing a glass soot deposit comprising: The reaction vessel comprises: an introduction duct that opens into a space different from the clean room and introduces air into the reaction vessel; a reaction vessel filter provided in the inlet duct for removing particles in the air introduced into the reaction vessel. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide a method for producing a soot glass deposit body and an apparatus for producing a soot glass deposit body that improve the operating rate of the entire production facility. [Brief description of the drawings]

[0011] [Figure 1]3A to 3C are diagrams showing a deposition process of the soot glass deposit body manufacturing apparatus according to the first embodiment; [Diagram 2] FIG. 4 is a diagram showing a non-deposition process of the soot glass deposit body manufacturing apparatus according to the first embodiment. [Diagram 3] FIG. 13 is a diagram showing a soot glass deposit manufacturing apparatus according to a second embodiment. [Figure 4] FIG. 13 is a diagram showing a soot glass deposit manufacturing apparatus according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Description of the embodiments of the present disclosure First, the embodiments of the present disclosure will be listed and described. A method for producing a soot glass deposit body according to one embodiment of the present disclosure includes the steps of: (1) a deposition step of depositing glass particles generated by a hydrolysis reaction caused by a burner flame on a target in a reaction vessel; a removing step of removing the soot glass deposit produced by the depositing step from the reaction vessel and transporting it to a clean room; A method for producing a soot glass deposit body, comprising: introducing air into the clean room through a clean room filter that removes particulates from the air; In the deposition step, air is introduced into the reaction vessel through a reaction vessel filter from a space different from the clean room. According to this configuration, the air introduced into the reaction vessel is introduced from a space different from the clean room. Since the air introduced into the reaction vessel passes through the reaction vessel filter, the cleanliness of the air introduced into the reaction vessel can be adjusted. Since the amount of air passing through the clean room filter is reduced, the frequency of the reaction vessel being stopped due to replacement of the clean room filter is also reduced, so that the operating rate of the entire manufacturing facility can be improved.

[0013] (2) Air may be introduced into the clean room through an air conditioner capable of adjusting temperature and humidity. According to this configuration, the consumption of temperature and humidity regulated air in the deposition process is reduced, thereby reducing the cost and effort associated with operating an air conditioner.

[0014] (3) In the method for producing a soot glass deposit body according to the above (1) or (2), in the depositing step, air drawn through an inlet duct opening to the outside may be introduced into the reaction vessel. According to this configuration, outdoor air is directly introduced, so that the configuration can be simplified.

[0015] (4) In the method for producing a glass soot deposit body according to (1) or (2) above, in the deposition step, air sucked from an inlet duct opening into a room other than the clean room and the reaction vessel may be introduced into the reaction vessel. According to this configuration, the influence of the outdoor environment such as outdoor wind can be reduced compared to when air is directly drawn in from outdoors. Also, when air is introduced into the room through a filter having a larger mesh than the reaction vessel filter, clogging of the reaction vessel filter can be suppressed.

[0016] (5) In the depositing step of the method for producing a soot glass deposit body according to any one of (1) to (4) above, air introduced into the reaction vessel may be subjected to total heat exchange with air in the clean room. According to this configuration, the air introduced into the reaction vessel also contributes to adjusting the temperature and humidity in the clean room, thereby reducing the cost and effort required for operating the air conditioner.

[0017] (6) In the method for producing a glass soot deposit body according to any one of (1) to (5) above, an intake duct opening to the outdoors and an exhaust port of the reaction vessel may be switched and connected to an exhaust pipe, and at the start of the deposition process, the exhaust pipe may be connected to the exhaust port, and at the end of the deposition process, the exhaust pipe may be connected to the intake duct and the exhaust port may be sealed. According to this configuration, the air inside the reaction vessel is not discharged except during the deposition process, so that the life of the reaction vessel filter is extended.

[0018] An apparatus for manufacturing a soot glass deposit body according to one aspect of the present disclosure includes: (7) A glass soot deposit manufacturing apparatus comprising: a reaction vessel for manufacturing a glass soot deposit body by depositing glass soot produced by a hydrolysis reaction using a burner flame on a target inside the reaction vessel; and a transport machine for transporting the manufactured glass soot deposit body to a clean room having an adjusted cleanliness level, wherein the reaction vessel is equipped with an inlet duct that opens into a space different from the clean room and introduces air into the reaction vessel, and a reaction vessel filter that is provided in the inlet duct and removes particles in the air introduced into the reaction vessel. According to this configuration, since air is introduced into the reaction vessel from a space other than the clean room, the consumption of air in the clean room can be suppressed, which extends the life of the clean room filter that adjusts the cleanliness level in the clean room and reduces the frequency of reaction vessel shutdowns due to replacement of the clean room filter, thereby improving the operating rate of the entire manufacturing facility.

[0019] DETAILED DESCRIPTION OF EMBODIMENTS OF THE DISCLOSURE Specific examples of a method for manufacturing a soot glass deposit body and an apparatus for manufacturing a soot glass deposit body according to an embodiment of the present disclosure will be described below with reference to the drawings. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0020] First embodiment Fig. 1 is a diagram showing a deposition process performed by the soot glass deposit manufacturing apparatus 1 according to the first embodiment. Fig. 2 is a diagram showing a non-deposition process performed by the soot glass deposit manufacturing apparatus 1 according to the first embodiment. As shown in Figs. 1 and 2, the soot glass deposit manufacturing apparatus 1 is housed in a clean room 2. Note that a clean room generally houses multiple reaction vessels, but only one reaction vessel is depicted in the drawings of the present disclosure.

[0021] The apparatus 1 for manufacturing a soot glass deposit body includes a reaction vessel 10 and a transporter 14. The reaction vessel 10 includes an outer vessel 11 and an inner vessel 12. The inner vessel 12 includes a burner B and a mesh-like wall portion 13. The apparatus 1 for manufacturing a soot glass deposit body manufactures a soot glass deposit body by depositing glass particles generated by a hydrolysis reaction caused by the flame of the burner B on a target T inside the reaction vessel 10. In this embodiment, the apparatus 1 for manufacturing a soot glass deposit body manufactures a soot glass deposit body by the OVD method in which glass particles are deposited by reciprocating a plurality of burners B parallel to the direction in which the target T extends.

[0022] The mesh wall portion 13 is formed by laminating a plurality of mesh plates made of a corrosion-resistant metal material such as nickel. The mesh wall portion 13 rectifies the flow of air flowing from the outer container 11 to the inner container 12 in the deposition process for depositing glass particles on the target T.

[0023] The transporter 14 transports the target T within the clean room 2, transports it from the clean room 2 into the reaction vessel 10, and removes the completed soot glass deposit from the reaction vessel 10 and transports it to the clean room 2. The completed soot glass deposit is stored in the clean room 2.

[0024] The clean room 2 is kept clean by removing particles by introducing air from outside through a clean room filter 3. This makes it possible to prevent impurities from adhering to the completed soot glass deposit body.

[0025] Moreover, in this embodiment, the clean room 2 has an air conditioner 4. The temperature and humidity inside the clean room 2 can be kept constant by adjusting the temperature and humidity of the air introduced by operating the air conditioner 4. If an inspection device is installed inside the clean room 2, it is desirable to control the temperature and humidity for a certain level of inspection accuracy. Furthermore, the air inside the clean room 2 that contains the soot glass deposit body may contain hydrogen chloride, and it is desirable to adjust the humidity in order to prevent hydrochloric acid generated by condensation from corroding the inside of the clean room 2.

[0026] The reaction vessel 10 has an introduction duct 15 that introduces air into the reaction vessel 10. In this embodiment, two introduction ducts 15 are provided. One end of the introduction duct 15 opens into the space between the outer vessel 11 and the inner vessel 12. In the first embodiment, the other end of the introduction duct 15 opens to the outdoors. The outdoors is an example of a space different from the clean room 2.

[0027] Furthermore, the reaction vessel 10 has a reaction vessel exhaust duct 18 that exhausts the air inside the reaction vessel 10. In Fig. 1, the reaction vessel exhaust duct 18 is connected to an exhaust pipe 9, but as described later, in some cases, an exhaust port 18a of the reaction vessel exhaust duct 18 may be sealed by a sealing part 19 (see also Fig. 2).

[0028] Furthermore, a first intake duct D1, a second intake duct D2, and a third intake duct D3, each having one end open to the outside, are provided in the clean room 2. The other end of the first intake duct D1 is connected to the reaction vessel exhaust duct 18. The other end of the third intake duct D3 is connected to the exhaust pipe 9.

[0029] As shown in FIG. 1 and FIG. 2, the second intake duct D2 switches between a state in which the other end of the second intake duct D2 is not connected to any duct and a state in which the other end of the second intake duct D2 is connected to the exhaust pipe 9. More specifically, in the deposition process (i.e., in a state in which the burner B is ignited), the other end of the second intake duct D2 is not connected to any pipe. However, in the non-deposition process (in a state in which the burner B is not ignited), the exhaust port 18a of the reaction vessel exhaust duct 18 is sealed by the sealing portion 19 as described above, and the second intake duct D2 moves so that the other end of the second intake duct D2 is connected to the exhaust pipe 9. In addition, the connection pipe portion between the reaction vessel exhaust duct 18 and the exhaust pipe 9 moves with the movement of the second intake duct D2.

[0030] The inlet duct 15 has a reaction vessel filter 16. The reaction vessel filter 16 is provided so as to pass air inside the inlet duct 15. In this embodiment, since two inlet ducts 15 are provided, the reaction vessel filter 16 is provided for each of the two inlet ducts 15. In addition, as shown in FIG. 1, it is preferable to provide an inlet fan 17 near the reaction vessel filter 16. The air sent by the inlet fan 17 passes through the reaction vessel filter 16, so that particles are removed from the air introduced into the reaction vessel 10. The reaction vessel filter 16 and the inlet fan 17 may be located in a space outside the clean room 2. In addition, the reaction vessel filter 16 does not necessarily have to be provided in the middle of the inlet duct 15. For example, the reaction vessel filter 16 and the inlet fan 17 may be provided at the opening of the inlet duct 15 (see also FIG. 3).

[0031] Next, the air flow related to the manufacturing apparatus 1 according to the first embodiment will be described. As shown in FIG. 1, in the deposition process, outside air is introduced from the introduction duct 15 by the operation of the introduction fan 17. The air that enters the introduction duct 15 has particles in the air removed by the reaction vessel filter 16 on the way. The air with improved cleanliness from which particles in the air have been removed is sent into the external vessel 11. The air in the external vessel 11 is taken into the internal vessel 12 through the mesh wall portion 13. The air sent into the reaction vessel 10, together with the gas generated in the deposition process, passes through the reaction vessel exhaust duct 18 and is exhausted from the exhaust pipe 9. At this time, the air is exhausted from the reaction vessel 10 while being mixed with the air taken in from the outdoors by the first intake duct D1 and the third intake duct D3. The air exhausted from the exhaust pipe 9 is sent to an exhaust gas treatment device (not shown).

[0032] 2, in the non-deposition step, air is not introduced into the reaction vessel 10, so there is no need to exhaust air from the reaction vessel exhaust duct 18. Furthermore, when burner B is ignited before moving from the non-deposition step to the deposition step, combustion gas (generally hydrogen, etc.) is ejected from burner B, and at this time, it is desirable not to send a large amount of combustion gas to the exhaust gas treatment device. In these cases, the sealing portion 19 seals the exhaust port 18a of the reaction vessel exhaust duct 18. It is desirable that a certain amount of air is always introduced into the exhaust gas treatment device, even when the exhaust port 18a is sealed by the sealing portion 19. In this case, a second intake duct D2 is connected to the exhaust pipe 9, and air introduced into the second intake duct D2 from outdoors is sent to the exhaust gas treatment device through the exhaust pipe 9.

[0033] In this way, in the deposition process, highly clean air (air containing a small number of particles) is intermittently introduced into the reaction vessel 10, and the same amount of air as the introduced air is exhausted from the reaction vessel 10. In addition, in the non-deposition process, the exhaust port 18a is sealed by the sealing portion 19, so that air is not exhausted from the reaction vessel 10.

[0034] In the manufacturing apparatus for soot glass deposit bodies as disclosed in Patent Document 1, air for the reaction vessel was sometimes introduced from a clean room. In such cases, the introduction duct was open into the clean room. This enabled highly clean air to be introduced into the reaction vessel.

[0035] However, when highly clean air is introduced from the clean room, it is necessary to introduce air into the clean room in the amount equal to the amount of air taken out from the clean room. When the air is introduced into the clean room, it passes through a clean room filter, so the clean room filter must be replaced as needed. In general, since multiple reaction vessels are connected to a common clean room, the operation of all reaction vessels is stopped when replacing the clean room filter. Furthermore, if the clean room is equipped with an air conditioner, there will be costs and labor associated with operating the air conditioner. The costs and labor associated with operating the air conditioner refer to the power costs of the air conditioning equipment, the operating costs of the cold or hot source, or both, and the costs and labor associated with maintenance work. These costs and labor increase the more air is introduced into the clean room (in other words, the air whose temperature and humidity are regulated).

[0036] Taking these points into consideration, the inventors have devised a method for producing a soot glass deposit body and a configuration of an apparatus 1 for producing a soot glass deposit body, which improve the operating rate of the entire production facility according to the present disclosure.

[0037] According to the method for producing a soot glass deposit body according to this embodiment, the air introduced into the reaction vessel 10 is introduced from a space different from the clean room 2. Since the air introduced into the reaction vessel 10 passes through the reaction vessel filter 16, it is possible to adjust the cleanliness of the air introduced into the reaction vessel 10. By reducing the amount of air taken out of the clean room 2, the amount of air passing through the clean room filter 3 is also reduced. This reduces the frequency of operation stoppages of the reaction vessel 10 due to replacement of the clean room filter 3, making it possible to improve the operating rate of the entire production facility. Incidentally, by providing the reaction vessel filter 16, it is necessary to replace the reaction vessel filter 16 as necessary. However, compared with the need to stop the operation of all reaction vessels 10 connected to the clean room 2 when replacing the clean room filter 3, it is only necessary to stop the operation of the reaction vessel 10 in which the reaction vessel filter 16 is provided when replacing the reaction vessel filter 16, so that the operating rate of the entire manufacturing facility is improved.

[0038] The clean room 2 is equipped with an air conditioner 4 capable of adjusting temperature and humidity. In the deposition process of the method for producing a soot glass deposit body according to this embodiment, consumption of temperature- and humidity-controlled air is suppressed, so that the cost and effort involved in operating the air conditioner 4 can be reduced.

[0039] In the method for producing a soot glass deposit body according to this embodiment, outdoor air is directly introduced into the reaction vessel 10 through the introduction duct 15, so that the method can be realized with a simple configuration.

[0040] In this embodiment, in a process other than the deposition process (non-deposition process), the exhaust port 18a is sealed by the sealing portion 19, so that the air inside the reaction vessel 10 is not discharged. Therefore, the life of the reaction vessel filter 16 is extended.

[0041] In the soot glass deposit manufacturing apparatus 1 according to this embodiment, the inlet duct 15 introduces air into the reaction vessel 10 from a space different from the clean room 2, so that it is possible to suppress the consumption of air within the clean room 2. This extends the life of the clean room filter 3 that adjusts the cleanliness level within the clean room 2, thereby improving the operating rate of the entire manufacturing facility.

[0042] Second Embodiment Next, a method for manufacturing a soot glass deposit body according to a second embodiment will be described. In the second and subsequent embodiments, the same components as those in the first embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 3 is a diagram showing a manufacturing apparatus 101 for a soot glass deposit body according to a second embodiment. A reaction vessel 110 of the manufacturing apparatus 101 for a soot glass deposit body according to the second embodiment is provided inside a room R1 on the floor below a clean room 102. The introduction duct 15 in the first embodiment opens to the outdoors and introduces outside air, whereas the introduction duct 115 in the second embodiment is different in that it opens to an indoor space (room R1) different from the clean room 102. The introduction duct 115 introduces indoor air into the reaction vessel 110 through a reaction vessel filter 116. Outdoor air may be introduced into the room R1 without adjusting the cleanliness, or air may be introduced through a filter with a coarser mesh than the clean room filter 3 that adjusts the cleanliness in the clean room 102. The temperature and humidity of the air in the room R1 may not be adjusted.

[0043] In the method for manufacturing a glass soot deposit body according to this embodiment, the inlet duct 115 draws in indoor air and introduces it into the reaction vessel 110, thereby reducing the effects of outdoor conditions such as outdoor wind compared to when air is drawn in directly from outdoors. Furthermore, when air is introduced from outdoors into the room R1 through a filter (not shown) that is coarser than the reaction vessel filter 116, clogging of the reaction vessel filter 116 can be suppressed, and the life of the reaction vessel filter 116 is extended.

[0044] Third embodiment Next, a method for manufacturing a soot glass deposit body according to a third embodiment will be described. FIG. 4 is a diagram showing a manufacturing apparatus 201 for a soot glass deposit body according to a third embodiment. A reaction vessel 210 of the manufacturing apparatus 201 for a soot glass deposit body according to the third embodiment is provided in a clean room 202, and an introduction duct 215 opens to an indoor space (room R2) different from the clean room 202 provided on the floor above the clean room 202, and to the outdoors. The introduction duct 215 adjusts the indoor air from the opening of the room R2 or the outdoor air from the opening of the outdoors with a valve and introduces it into the reaction vessel 210. In the third embodiment, the introduction duct 215 has a structure in which one duct branches midway, so that air is introduced into the reaction vessel 210 from two places. The introduction duct 215 is provided with an introduction fan 217 for drawing in the air of the room R2 or the outdoor air. The air drawn into the introduction duct 215 by the introduction fan 217 is introduced into the reaction vessel 210 through a reaction vessel filter 216. Outdoor air may be introduced into room R2 without adjusting the cleanliness level, or air may be introduced through a filter with a coarser mesh than the clean room filter 3 that adjusts the cleanliness level inside the clean room 202. In addition, the temperature and humidity of the air in room R2 do not need to be adjusted.

[0045] The clean room 202 has a circulation path 221 that circulates air within the clean room 202. A circulation fan 222 for sucking air within the clean room 202 is provided in the circulation path 221. The air sucked into the circulation path 221 by the circulation fan 222 passes through a circulation path filter 223 provided midway along the circulation path 221, and is returned to the clean room 202 again. By circulating the air through the circulation path filter 223, the cleanliness within the clean room 202 can be maintained for a longer period of time.

[0046] Further, total heat exchange is performed by the total heat exchanger 224 between the air passing through the circulation path 221 and the air passing through the introduction duct 215. The total heat exchange indicates the exchange of temperature, humidity, or both. In other words, in the total heat exchange, only the temperature may be exchanged, only the humidity may be exchanged, or both the temperature and the humidity may be exchanged.

[0047] The total heat exchanger 224 performs total heat exchange between the air passing through the circulation path 221 and the air passing through the introduction duct 215, thereby reducing the operating costs of the air conditioner 4. The reason for this will be explained below with a specific example.

[0048] Generally, when the outdoor air is hotter and more humid than the air inside the clean room 202, the air introduced into the clean room 202 is first cooled to a temperature lower than the temperature of the air inside the clean room 202. This reduces the amount of saturated water vapor in the air introduced into the clean room 202, and some of the water vapor in the air condenses. By removing the condensed water, the amount of water vapor in the air decreases, and the humidity decreases. The air is then warmed to the temperature of the air inside the clean room 202. By using this principle with appropriate adjustments, the air inside the clean room 202 can be adjusted to an appropriate temperature and humidity.

[0049] In this way, when adjusting the humidity, the air conditioner 4 may intentionally cool the air to a temperature lower than the appropriate temperature, or conversely, heat the air to a temperature higher than the appropriate temperature. In such a case, the air conditioner 4 can assist in adjusting the temperature and humidity of the air in the clean room 202 by performing total heat exchange with the air introduced into the reaction vessel 210. This can reduce the operating load and operating costs of the air conditioner 4. In addition, in order to more effectively assist in adjusting the temperature and humidity, the air introduced into the reaction vessel 210 may be switched between or mixed with the air introduced from the room R2 and the air introduced from the outdoors.

[0050] Thus, according to the method for producing a soot glass deposit body in this embodiment, the air introduced into the reaction vessel 210 also contributes to adjusting the temperature and humidity of the air in the clean room 202. This makes it possible to reduce the load and costs associated with the operation of the air conditioner 4.

[0051] (Experimental Example) Next, the lifespan of the clean room filter in the conventional method for producing a soot glass deposit body (hereinafter referred to as the comparative example) was compared with that in the method for producing a soot glass deposit body according to the first to third embodiments. Note that the comparative example is a method in which air is taken out of the clean room and introduced into the reaction vessel during the deposition process.

[0052] The above four forms including the comparative example were compared in terms of the amount of air taken out of the clean room, the operating load of the air conditioner, the life of the clean room filter, the properties of the air introduced into the reaction vessel, the cleanliness of the clean room, and the frequency of occurrence of optical fiber quality defects. The results are shown in Table 1. The amount of air taken out of the clean room, the operating load of the air conditioner, the life of the clean room filter, and the frequency of occurrence of optical fiber quality defects are shown as approximate percentages when the values ​​of the comparative example are all set to 1. The cleanliness of the clean room shows the approximate percentage of the dust count when the dust count value in the comparative example is set to 1. The "frequency of occurrence of optical fiber quality defects" shows the degree of occurrence of defective products that occurs when optical fiber is produced based on the glass particle deposit produced by each method. In addition, the "properties of the air introduced into the reaction vessel" are shown in terms of the cleanliness, temperature, and humidity. Among these, the cleanliness shows the dust count.

[0053] [Table 1]

[0054] As shown in Table 1, the amount of air taken out of the clean room in the first embodiment is 0.1 times or less compared to the comparative example. Also, the amount of air taken out of the clean room in the second and third embodiments is 0.05 times or less compared to the comparative example. Since the amount of new air introduced into the clean room is the same as the amount of air taken out of the clean room, in the manufacturing methods according to the first to third embodiments, the operating load on the air conditioner is reduced and the life of the clean room filter is extended.

[0055] Specifically, the operating load of the air conditioner is approximately proportional to the amount of air taken out of the clean room. That is, the operating load of the air conditioner in the first embodiment is 0.1 times or less compared to the comparative example. Also, the operating load of the air conditioner in the second and third embodiments is 0.05 times or less compared to the comparative example.

[0056] On the other hand, the lifespan of the clean room filter is approximately inversely proportional to the amount of air carried out from the clean room. That is, the lifespan of the clean room filter of the first embodiment is about 10 times longer than that of the comparative example. Also, the lifespan of the clean room filters of the second and third embodiments is about 20 times longer than that of the comparative example.

[0057] As shown in Table 1, the properties of the air introduced into the reaction vessel and the cleanliness of the clean room are different between the comparative example and each embodiment. Regarding the degree of cleanliness, since air is introduced into the reaction vessel after passing through a filter, the difference in the degree of cleanliness is relatively small in each example, but the difference in temperature and humidity is relatively large between the comparative example and each embodiment.

[0058] In the comparative example, the temperature and humidity are adjusted by an air conditioner, so that air with a temperature of 20° C. to 30° C. and a humidity of 20% to 60% is introduced into the reaction vessel. On the other hand, in the first and second embodiments, the air introduced into the reaction vessel is not temperature and humidity regulated. Therefore, in both embodiments, air having a temperature of 0° C. or more and 40° C. or less and a humidity of 10% or more and 100% or less is introduced into the reaction vessel. In the third embodiment, total heat exchange is performed by a total heat exchanger. This narrows the range of temperature and humidity of the air introduced into the reaction vessel compared to the first and second embodiments. In the third embodiment, air with a temperature of 5°C to 35°C and a humidity of 15% to 95% is introduced into the reaction vessel.

[0059] Furthermore, there is a difference in the cleanliness of the clean room between the comparative example and the third embodiment and the first and second embodiments. In the comparative example, air in the clean room is taken out and introduced into the reaction vessel. Then, the amount of air taken out of the clean room is introduced from the outside through a clean room filter. As a result, the frequency of air circulation is higher than in the first and second embodiments, and the degree of cleanliness is lower than in the first and second embodiments. In other words, since the first and second embodiments take out less air from within the clean room, the cleanliness value is about 20% higher than in the comparative example. On the other hand, in the third embodiment, the air in the clean room is circulated by a circulation path. In addition, a circulation path filter is provided in the circulation path, and the circulation path filter can remove particles from the air passing through the circulation path. As a result, the cleanliness of the clean room is about the same as that of the comparative example.

[0060] In this way, the comparative example and each embodiment manufacture a soot glass deposit body under different conditions in terms of the properties of the air introduced into the reaction vessel and the cleanliness of the clean room. However, as shown in Table 1, no matter which of the exemplary methods is used to manufacture the soot glass deposit body, the frequency of occurrence of optical fiber quality defects remains almost unchanged. In other words, it has been shown that the soot glass deposit body manufacturing method according to the present disclosure can provide a soot glass deposit body of the same quality as the comparative example.

[0061] Although the present disclosure has been described in detail and with reference to specific embodiments, it is clear to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present disclosure. Furthermore, the number, position, shape, etc. of the components described above are not limited to the above embodiments, and can be changed to the number, position, shape, etc. that are suitable for implementing the present disclosure.

[0062] For example, in each of the embodiments described in the present disclosure, an example of manufacturing a soot glass deposit body by the OVD method has been shown, but the present disclosure is not limited to the examples of the embodiments and can be applied to the case of manufacturing a soot glass deposit body by other vapor phase synthesis methods. [Explanation of symbols]

[0063] 1,101,201 Manufacturing equipment 2,102,202 Clean Rooms 3. Clean Room Filters 4 Air conditioner 9. Exhaust pipe 10,110,210 Reaction vessel 11 Outer container 12 Inner Container 13 Mesh wall 14 Transport Machine 15,115,215 Inlet duct 16,116,216 Reactor Filter 17 Introductory Fan 18 Reactor Exhaust Duct 18a Exhaust port 19 Sealing part 217 Introductory Fan 221 Circulation route 222 Circulation Fan 223 Circulation Filter 224 Total heat exchanger B Burner D1 First intake duct D2 Second intake duct D3 Third intake duct R1 Room R2 Room T Target

Claims

1. a deposition step of depositing glass particles generated by a hydrolysis reaction caused by a flame of a burner on a target in a reaction vessel; a removing step of removing the soot glass deposit produced by the depositing step from the reaction vessel and transporting it to a clean room; A method for producing a soot glass deposit body, comprising: introducing air into the clean room through a clean room filter that removes particulates from the air; In the deposition step, air is introduced into the reaction vessel through a reaction vessel filter from a space different from the clean room. A method for producing a soot glass deposit.

2. 2. The method for producing a soot glass deposit body according to claim 1, wherein air is introduced into the clean room through an air conditioner capable of adjusting temperature and humidity.

3. 2. The method for producing a soot glass deposit body according to claim 1, wherein in said depositing step, air is sucked through an inlet duct opening to the outside and introduced into said reaction vessel.

4. 2. The method for producing a soot glass deposit body according to claim 1, wherein in the depositing step, air is introduced into the reaction vessel through an inlet duct that opens into a room different from the clean room and the reaction vessel.

5. 2. The method for producing a soot glass deposit body according to claim 1, wherein in the depositing step, the air introduced into the reaction vessel is subjected to total heat exchange with air in the clean room.

6. An intake duct opening to the outside and an exhaust port of the reaction vessel are switched and connected to an exhaust pipe; At the start of the deposition process, connecting the exhaust pipe to the exhaust port; 6. The method for producing a soot glass deposit body according to claim 1, further comprising the steps of: connecting the exhaust pipe to the intake duct and sealing the exhaust port when the depositing step is completed.

7. a reaction vessel in which glass particles generated by a hydrolysis reaction caused by a flame of a burner are deposited on a target to produce a glass particle deposit; a conveyor for conveying the produced soot glass deposit body to a clean room whose cleanliness is adjusted; An apparatus for manufacturing a glass soot deposit comprising: The reaction vessel comprises: an introduction duct that opens into a space different from the clean room and introduces air into the reaction vessel; A reaction vessel filter provided in the inlet duct for removing particles in the air introduced into the reaction vessel. A manufacturing device for glass particulate deposits.

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