Optical fiber manufacturing device and optical fiber manufacturing method

Abstract

The invention provides an optical fiber manufacturing device and an optical fiber manufacturing method, which can restrain atmosphere from flowing into a cooling device using hydrogen for cooling. The optical fiber manufacturing device is provided with: a drawing furnace for heating and melting an optical fiber base material and drawing the optical fiber base material; the cooling device is used for cooling the drawn glass fibers; the preparation chamber is arranged at the upper end of the cooling device; a hydrogen gas supply device for supplying hydrogen gas into the cooling device; and an inert gas supply device for supplying an inert gas into the preparation chamber.

Description

Technical Field

[0001] The present disclosure relates to an optical fiber manufacturing device and an optical fiber manufacturing method. Background Art

[0002] Patent Documents 1 and 2 disclose an optical fiber drawing device that cools a glass fiber drawn out from a drawing furnace using a cooling device supplied with helium (He) gas.

[0003] Patent Document 3 discloses an optical fiber drawing device that cools a glass fiber drawn out from a drawing furnace using a cooling device supplied with hydrogen gas.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2000-103649

[0007] Patent Document 2: Japanese Patent Application Publication No. 2005-119901

[0008] Patent Document 3: Japanese Patent Application Laid-Open No. 6-157065 Summary of the invention

[0009] Technical Problems to be Solved by the Invention

[0010] As mentioned above, in optical fiber manufacturing equipment, the use of hydrogen gas, which is easily available and has high thermal conductivity, as an inert gas for cooling glass fibers is being studied as a substitute for helium. However, hydrogen gas is a flammable gas, and the explosive concentration range of hydrogen in the atmosphere is 4 to 75%, requiring the implementation of explosion-proof measures.

[0011] An object of the present disclosure is to provide an optical fiber manufacturing apparatus and a manufacturing method that suppress the inflow of atmospheric air into a cooling apparatus that uses hydrogen gas for cooling.

[0012] Technical solutions for solving technical problems

[0013] An optical fiber manufacturing device disclosed herein comprises:

[0014] Wire drawing furnace, heating and melting the optical fiber mother material and drawing;

[0015] A cooling device is used to cool the drawn glass fibers;

[0016] A preparatory chamber, arranged at the upper end of the cooling device;

[0017] a hydrogen supply device for supplying hydrogen into the cooling device; and

[0018] The inert gas supply device supplies the inert gas into the preparation chamber.

[0019] Effects of the Invention

[0020] According to the present disclosure, it is possible to provide an optical fiber manufacturing apparatus and a method for manufacturing an optical fiber that suppress the inflow of atmospheric air into a cooling apparatus that performs cooling using hydrogen gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a conceptual diagram showing the structure of the optical fiber manufacturing apparatus according to the first embodiment.

[0022] Figure 2 It is shown Figure 1 A schematic diagram of a structural example of a preparatory chamber and a cooling device of an optical fiber manufacturing device.

[0023] Figure 3 It is a schematic diagram showing a configuration example of a preliminary chamber and a cooling device of an optical fiber manufacturing apparatus according to Modification 1.

[0024] Figure 4 It is a schematic diagram showing a configuration example of a preliminary chamber and a cooling device of an optical fiber manufacturing apparatus according to Modification 2.

[0025] Figure 5 It is a schematic diagram showing a configuration example of a preliminary chamber and a cooling device of an optical fiber manufacturing apparatus according to Modification 3.

[0026] Figure 6 It is a conceptual diagram showing the structure of the optical fiber manufacturing apparatus according to the second embodiment.

[0027] Figure 7 It is shown Figure 6 A schematic diagram of a structural example of a cooling device for an optical fiber manufacturing device.

[0028] Figure 8 It is a schematic diagram showing a configuration example of a preliminary chamber and a cooling device of an optical fiber manufacturing apparatus according to Modification 4.

[0029] Fig. 9 It is a schematic diagram showing a configuration example of a preliminary chamber and a cooling device of an optical fiber manufacturing apparatus according to Modification 5. DETAILED DESCRIPTION

[0030] [Description of Embodiments of the Present Disclosure]

[0031] First, the contents of the embodiments of the present disclosure are listed and described.

[0032] (1) The optical fiber manufacturing device disclosed in the present invention comprises:

[0033] Wire drawing furnace, heating and melting the optical fiber mother material and drawing;

[0034] A cooling device is used to cool the drawn glass fibers;

[0035] A preparatory chamber, arranged at the upper end of the cooling device;

[0036] a hydrogen supply device for supplying hydrogen into the cooling device; and

[0037] The inert gas supply device supplies the inert gas into the preparation chamber.

[0038] According to the above structure, since the glass fiber passes through the preparatory chamber supplied with inert gas just before entering the cooling device, the atmosphere around the glass fiber pulled by the glass fiber traveling at high speed is replaced with inert gas in the preparatory chamber. Thus, it is possible to suppress the inflow of the atmosphere into the cooling device using hydrogen for cooling.

[0039] In this specification, the expression “arranged at the upper end of the cooling device” is not limited to a structure in which the preliminary chamber is arranged only at the upper end of the cooling device, but also includes a structure in which at least a part of the preliminary chamber is arranged at the upper end of the cooling device.

[0040] (2) Alternatively, in (1) above,

[0041] A plurality of the preparatory chambers are stacked on the upper end of the cooling device,

[0042] The inert gas supply device is configured to supply the inert gas to each of the plurality of preliminary chambers.

[0043] According to the above configuration, by providing a plurality of preliminary chambers, the atmosphere around the glass fibers can be more reliably replaced with an inert gas.

[0044] (3) In the above (1) or (2), an oxygen concentration meter for measuring the oxygen concentration in the spare chamber may be provided.

[0045] According to the above configuration, by measuring the oxygen concentration in the preliminary chamber, it is possible to confirm the effect of replacing the air (oxygen) in the preliminary chamber with the inert gas.

[0046] (4) In the above (3), when the value of the oxygen concentration measured by the oxygen concentration meter exceeds a predetermined value, the hydrogen gas supply device may stop supplying the hydrogen gas to the cooling device.

[0047] According to the above configuration, even when the oxygen concentration in the spare chamber increases, by stopping the supply of hydrogen gas into the cooling device, it is possible to prevent hydrogen explosion caused by the inflow of atmospheric air into the cooling device.

[0048] (5) In any one of the above (1) to (4), the auxiliary chamber may be configured to cover the entire cooling device.

[0049] According to the above structure, when the cooling device is double-framed, the outer frame can be used as a preparatory chamber. In addition, since the lower end of the cooling device is also covered by the preparatory chamber, the hydrogen drawn by the glass fiber drawn out from the cooling device can be replaced with an inert gas.

[0050] (6) The optical fiber manufacturing device of the present disclosure comprises:

[0051] Wire drawing furnace, heating and melting the optical fiber mother material and drawing;

[0052] A cooling device is used to cool the drawn glass fibers;

[0053] a hydrogen supply device for supplying hydrogen into the cooling device; and

[0054] A hydrogen recovery device recovers the hydrogen supplied to the cooling device,

[0055] A hydrogen recovery port for recovering the hydrogen in the cooling device is provided at the lower part of the cooling device.

[0056] According to the above configuration, since hydrogen gas is recovered from the vicinity of the opening through which the glass fibers are led out of the cooling device, it is possible to suppress the hydrogen gas drawn by the glass fibers running in the cooling device from flowing out of the cooling device.

[0057] (7) In the above (6), the following may be included:

[0058] a preparatory chamber, disposed at an upper end of the cooling device; and

[0059] The inert gas supply device supplies the inert gas into the preparation chamber.

[0060] According to the above structure, since the glass fiber passes through the preparatory chamber supplied with inert gas just before entering the cooling device, the atmosphere around the glass fiber pulled by the glass fiber traveling at high speed is replaced with inert gas in the preparatory chamber. Thus, it is possible to suppress the inflow of the atmosphere into the cooling device using hydrogen for cooling.

[0061] (8) In the above (7), the auxiliary chamber may be configured to cover the entire cooling device.

[0062] According to the above structure, when the cooling device is double-framed, the outer frame can be used as a preparatory chamber. In addition, since the lower end of the cooling device is also covered by the preparatory chamber, the hydrogen drawn by the glass fiber drawn out from the cooling device can be replaced with an inert gas.

[0063] (9) A method for manufacturing an optical fiber, comprising:

[0064] The drawing process is to heat and melt the optical fiber mother material and then draw it;

[0065] a cooling step of cooling the drawn glass fiber by passing the drawn glass fiber through a cooling device supplied with hydrogen; and

[0066] The replacement step is to replace the atmosphere around the glass fiber with the inert gas by passing the glass fiber through a preliminary chamber disposed at an upper end of the cooling device and supplied with the inert gas before the cooling step.

[0067] According to the above method, since the glass fiber passes through the preparatory chamber supplied with inert gas just before entering the cooling device, the atmosphere around the glass fiber pulled by the glass fiber traveling at high speed is replaced with the inert gas in the preparatory chamber. Thus, it is possible to suppress the inflow of the atmosphere into the cooling device using hydrogen for cooling.

[0068] (10) A method for manufacturing an optical fiber, comprising:

[0069] The drawing process is to heat and melt the optical fiber mother material and then draw it;

[0070] a cooling step of cooling the drawn glass fiber by passing the drawn glass fiber through a cooling device supplied with hydrogen; and

[0071] The recovery step is to recover the hydrogen gas in the cooling device at a lower portion of the cooling device.

[0072] According to the above method, since hydrogen gas is recovered from the vicinity of the opening through which the glass fibers are led out of the cooling device, it is possible to suppress the hydrogen gas drawn by the glass fibers running in the cooling device from flowing out of the cooling device.

[0073] [Details of the embodiments of the present disclosure]

[0074] Specific examples of the manufacturing device and method of manufacturing optical fiber according to the embodiments of the present disclosure are described below with reference to the accompanying drawings. It should be noted that the present invention is not limited to these examples, but is represented by the patent claims, and is intended to include all changes within the meaning and scope equivalent to the patent claims. In addition, in the drawings used in the following description, the scale is appropriately changed in order to make each component a recognizable size.

[0075] [First embodiment]

[0076] (Optical fiber manufacturing device 1)

[0077] Figure 1 1 is a schematic diagram showing the structure of an optical fiber manufacturing device 1 according to the first embodiment. Figure 1 As shown, the optical fiber manufacturing device 1 includes a drawing furnace 2, a preparatory chamber 3, a cooling device 4, a resin coating device 5, a resin curing device 6, a winding device 7, an inert gas supply device 8, a hydrogen supply device 9 and a control device 10.

[0078] The drawing furnace 2 includes a furnace core tube 21 and a heater 22. The optical fiber preform G supplied into the furnace core tube 21 is heated and melted by the heater 22, and is drawn so that glass fibers G1 having a predetermined outer diameter are continuously obtained.

[0079] The preparatory chamber 3 is provided at the upper end of the cooling device 4. An inert gas is supplied from an inert gas supply device 8 to the preparatory chamber 3 via a gas pipe 81. The glass fiber G1 drawn from the drawing furnace 2 passes through the preparatory chamber 3. When the glass fiber G1 passes through the preparatory chamber 3, the atmosphere drawn by the glass fiber G1 and wound around the glass fiber G1 is replaced with an inert gas. The inert gas is, for example, argon gas and nitrogen gas.

[0080] The cooling device 4 is configured to cool the glass fiber G1. Hydrogen is supplied from the hydrogen supply device 9 to the cooling device 4 via the gas pipe 91. Figure 1 9, a part of the gas piping 91a is omitted from the figure, but the gas piping 91a is connected to the hydrogen supply device 9. The glass fiber G1 that has passed through the preparatory chamber 3 passes through the cooling device 4. The glass fiber G1 is cooled by the hydrogen while passing through the cooling device 4. In addition, an inert gas is supplied from the inert gas supply device 8 to the cooling device 4 via the gas piping 82. The inside of the cooling device 4 is pressurized by the inert gas.

[0081] The resin coating device 5 is configured to coat the glass fiber G1 with resin. The resin curing device 6 is configured to cure the resin coated around the glass fiber G1. The optical fiber G2 after the resin curing is wound by the winding device 7.

[0082] The control device 10 controls the operation of each device. For example, the control device 10 adjusts the drawing speed of the glass fiber G1 by controlling the operation of the drawing furnace 2 and the winding device 7. For example, the control device 10 adjusts the supply amount of hydrogen supplied to the cooling device 4 by controlling the operation of the hydrogen supply device 9. The control device 10 is composed of, for example, a general-purpose computer having a general-purpose memory and a general-purpose microprocessor that cooperates with the general-purpose memory.

[0083] Next, use Figure 2 The structures of the preliminary chamber 3 and the cooling device 4 will be described in detail.

[0084] like Figure 2As shown, the preparatory chamber 3 is arranged at the upper end of the cooling device 4 in a state of contacting the upper end of the cooling device 4. A first opening 31 for introducing the glass fiber G1 is provided at the upper end of the preparatory chamber 3. A second opening 32 for leading out the glass fiber G1 is provided at the lower end of the preparatory chamber 3. The drawn glass fiber G1 enters the preparatory chamber 3 from the first opening 31, passes through the preparatory chamber 3, and is led out from the second opening 32.

[0085] A gas supply port 33 for supplying an inert gas is provided on the side of the preparatory chamber 3. One end of a gas pipe 81 is connected to the gas supply port 33. The other end of the gas pipe 81 is connected to an inert gas supply device 8 (see Figure 1 The inert gas supplied from the inert gas supply device 8 is supplied into the preparatory chamber 3 from the gas supply port 33 through the gas pipe 81 .

[0086] A first opening 41 for introducing the glass fiber G1 is provided at the upper end of the cooling device 4. The first opening 41 is formed to communicate with the second opening 32 of the preparatory chamber 3. A second opening 42 for leading out the glass fiber G1 is provided at the lower end of the cooling device 4. The glass fiber G1 that has passed through the preparatory chamber 3 enters the cooling device 4 from the first opening 41, passes through the cooling device 4, and is led out from the second opening 42.

[0087] A gas supply port 43 for supplying an inert gas is provided on the side of the cooling device 4. In this example, the gas supply port 43 is provided below the center in the longitudinal direction (the vertical direction in the figure). One end of a gas pipe 82 is connected to the gas supply port 43. The other end of the gas pipe 82 is connected to an inert gas supply device 8 (see FIG. 1 ). Figure 1 The inert gas supplied from the inert gas supply device 8 is supplied into the preparatory chamber 3 from the gas supply port 43 through the gas pipe 82 .

[0088] A gas supply port 44 for supplying hydrogen is provided on the side surface of the upper portion of the cooling device 4. One end of a gas pipe 91 is connected to the gas supply port 44. The other end of the gas pipe 91 is connected to a hydrogen supply device 9 (see Figure 1 ). The hydrogen supplied from the hydrogen supply device 9 is supplied from the gas supply port 44 to the cooling device 4 through the gas pipe 91. In this example, the gas supply port 44a and the gas supply port 44b are arranged at opposite positions, and the hydrogen supplied from the hydrogen supply device 9 is supplied from the gas supply port 44a and the gas supply port 44b to the cooling device 4 through the gas pipe 91a and the gas pipe 91b. It should be noted that, in this example, the gas pipe 91a and the gas pipe 91b extend to the inner side of the gas supply port 44a and the gas supply port 44b, and the hydrogen is supplied to a position closer to the glass fiber G1.

[0089] The cooling device 4 has a cooling passage 45 therein. A cooling medium flows in the cooling passage 45 .

[0090] [Optical fiber manufacturing method]

[0091] Next, a method for producing an optical fiber using the optical fiber production apparatus 1 will be described.

[0092] First, the optical fiber base material G is heated and melted in the drawing furnace 2 and drawn (drawing process). Specifically, the optical fiber base material G is suspended in the furnace core tube 21 by a base material suspension mechanism (not shown), and the lower part of the optical fiber base material G is heated and melted by a heater 22. The molten optical fiber base material G becomes a glass fiber G1 of a predetermined outer diameter by the weight of the molten glass and the tensile force, and is continuously drawn.

[0093] The drawn glass fiber G1 continuously passes through the preparatory chamber 3 before passing through the cooling device 4. The inert gas is supplied from the inert gas supply device 8 into the preparatory chamber 3, and the atmosphere around the glass fiber G1 passing through the preparatory chamber 3 is replaced with the inert gas (replacement process). For example, the preparatory chamber 3 is pressurized positively by the inert gas to suppress the atmosphere drawn by the glass fiber G1 from flowing into the preparatory chamber 3.

[0094] The glass fiber G1 that has passed through the preliminary chamber 3 continuously passes through the cooling device 4. Since the cooling device 4 is provided at the lower end of the preliminary chamber 3, the glass fiber G1 that has passed through the preliminary chamber 3 is not exposed to the atmosphere, but is introduced into the cooling device 4. Hydrogen is supplied from the hydrogen supply device 9 to the cooling device 4, and the glass fiber G1 that has passed through the cooling device 4 is cooled by the hydrogen (cooling process). In this example, the hydrogen is cooled by the cooling solvent that flows in the cooling passage 45, and the glass fiber G1 that has passed through the cooling device 4 is cooled by the cooled hydrogen.

[0095] In addition, inert gas is supplied from the inert gas supply device 8 into the cooling device 4 , and the inert gas is used to make the inside of the cooling device 4 positively pressurized, thereby suppressing the air drawn by the glass fiber G1 from flowing into the cooling device 4 .

[0096] The glass fiber G1 that has passed through the cooling device 4 is coated with resin by the resin coating device 5. Then, the resin coated around the glass fiber G1 is cured by the resin curing device 6 to form the optical fiber G2. The optical fiber G2 is wound by the winding device 7.

[0097] Here, hydrogen gas used as the refrigerant gas of the cooling device 4 is easier to obtain than helium gas, and since its thermal conductivity is higher than that of helium gas, the glass fiber G1 can be effectively cooled. Thus, even when the drawing speed of the glass fiber G1 is high, the glass fiber G1 can be sufficiently cooled, so the productivity of the optical fiber G2 is improved. On the other hand, hydrogen gas is a flammable gas, and when mixed with the air (oxygen) at a concentration above a certain value, it may cause an explosion.

[0098] According to the optical fiber manufacturing apparatus 1 and the optical fiber manufacturing method according to the first embodiment, since the glass fiber G1 passes through the preparatory chamber 3 supplied with the inert gas immediately before entering the cooling device 4, the atmosphere drawn by the glass fiber G1 traveling at a high speed and entangled around the glass fiber G1 is replaced with the inert gas in the preparatory chamber 3. Thus, it is possible to suppress the atmosphere from flowing into the cooling device 4 supplied with hydrogen.

[0099] In addition, in the present embodiment, since the inert gas is supplied into the cooling device 4, the inside of the cooling device 4 is positively pressurized, and the atmosphere drawn by the glass fiber G1 can be further suppressed from flowing into the cooling device 4. The hydrogen gas is diluted by the inert gas in the cooling device 4 and discharged from the second opening 42. The flow rates of the inert gas and hydrogen gas supplied into the cooling device 4 are set so that they will not explode even if mixed with the atmosphere.

[0100] It should be noted that, in the present embodiment, the inert gas is used to positively pressurize the preparatory chamber 3, thereby suppressing the atmospheric air drawn by the glass fiber G1 from flowing into the preparatory chamber 3. However, for example, a gas discharge port (not shown) may be provided in the preparatory chamber 3, and the atmospheric air drawn by the glass fiber G1 and flowing into the preparatory chamber 3 may be squeezed out by the inert gas and discharged from the gas discharge port.

[0101] (Variant 1)

[0102] In the first embodiment described above, one preparatory chamber 3 is disposed at the upper end of the cooling device 4. However, a plurality of preparatory chambers 3 may be disposed in a stacked manner at the upper end of the cooling device 4.

[0103] Figure 3 FIG. 1 shows a configuration example of an optical fiber manufacturing apparatus 1A according to Modification 1. Figure 2 Compared with the optical fiber manufacturing apparatus 1 shown, the structure of the preliminary chamber 3 is different. For the sake of convenience, the description of the components having the same reference numerals as those already described in the description of the first embodiment is omitted.

[0104] like Figure 3As shown, in the optical fiber manufacturing apparatus 1A according to Modification 1, two preparatory chambers 3a and 3b are stacked and arranged on the upper end of the cooling device 4. Specifically, the preparatory chamber 3b is arranged on the upper end of the cooling device 4, and the preparatory chamber 3a is arranged on the upper end of the preparatory chamber 3b.

[0105] A first opening 31a for introducing the glass fiber G1 is provided at the upper end of the preparatory chamber 3a. A second opening 32a for leading out the glass fiber G1 is provided at the lower end of the preparatory chamber 3a. A gas supply port 33a for supplying an inert gas is provided on the side of the preparatory chamber 3a. One end of the gas pipe 81a is connected to the gas supply port 33a. The other end of the gas pipe 81a is connected to the inert gas supply device 8 (see Figure 1 The inert gas supplied from the inert gas supply device 8 is supplied from the gas supply port 33a into the preparatory chamber 3a through the gas pipe 81a.

[0106] A first opening 31b for introducing the glass fiber G1 is provided at the upper end of the preparatory chamber 3b. The first opening 31b is formed to communicate with the second opening 32a of the preparatory chamber 3a. A second opening 32b for leading out the glass fiber G1 is provided at the lower end of the preparatory chamber 3b. The second opening 32b is formed to communicate with the first opening 41 of the cooling device 4. A gas supply port 33b for supplying an inert gas is provided on the side of the preparatory chamber 3b. One end of the gas pipe 81b is connected to the gas supply port 33b. The other end of the gas pipe 81b is connected to the inert gas supply device 8 (see Figure 1 The inert gas supplied from the inert gas supply device 8 is supplied from the gas supply port 33b into the preparatory chamber 3b through the gas pipe 81b.

[0107] The glass fiber G1 drawn from the drawing furnace 2 continuously passes through the preparatory chamber 3a and the preparatory chamber 3b before passing through the cooling device 4. Inert gas is supplied from the inert gas supply device 8 to the preparatory chamber 3a, and the atmosphere around the glass fiber G1 passing through the preparatory chamber 3a is replaced with the inert gas.

[0108] In addition, the inert gas is supplied from the inert gas supply device 8 into the preliminary chamber 3 b , and the atmosphere around the glass fibers G1 passing through the preliminary chamber 3 b is replaced with the inert gas.

[0109] According to the optical fiber manufacturing apparatus 1A according to Modification 1, the glass fiber G1 passes through the two preparatory chambers 3a and 3b supplied with inert gas immediately before entering the cooling device 4, so that the atmosphere around the glass fiber G1 can be replaced with the inert gas more reliably.

[0110] It should be noted that in this modification, a gas exhaust port (not shown) may be provided in each of the preparatory chambers 3a and 3b, and the atmosphere drawn by the glass fiber G1 and flowing into the preparatory chambers 3a and 3b may be squeezed out by the inert gas and exhausted from the gas exhaust port.

[0111] In the present modification, three or more preparatory chambers 3 may be stacked and arranged on the upper end of the cooling device 4 .

[0112] (Variant 2)

[0113] In the first embodiment, preliminary chamber 3 is provided only at the upper end of cooling device 4. However, preliminary chamber 3 may be provided to cover the entire cooling device 4 including the side and lower end thereof in addition to the upper end thereof.

[0114] Figure 4 FIG. 2 shows a configuration example of an optical fiber manufacturing apparatus 1B according to Modification 2. Figure 2 Compared with the optical fiber manufacturing apparatus 1 shown, the structure of the preliminary chamber 3 is different. For the sake of convenience, the description of the components having the same reference numerals as those already described in the description of the first embodiment is omitted.

[0115] like Figure 4 As shown, an optical fiber manufacturing apparatus 1B according to Modification 2 includes a preliminary chamber 3A configured to cover the entire cooling device 4 .

[0116] A first opening 31A for introducing the glass fiber G1 is provided at the upper end of the preparatory chamber 3A. A second opening 32A for leading out the glass fiber G1 is provided at the lower end of the preparatory chamber 3A. A gas supply port 33A for supplying an inert gas is provided on the side of the preparatory chamber 3A. One end of the gas pipe 81 is connected to the gas supply port 33A. The other end of the gas pipe 81 is connected to the inert gas supply device 8 (see Figure 1 The inert gas supplied from the inert gas supply device 8 is supplied from the gas supply port 33A into the preparatory chamber 3A through the gas pipe 81 .

[0117] The glass fiber G1 drawn from the drawing furnace 2 enters the preparatory chamber 3A before passing through the cooling device 4. The inert gas is supplied to the preparatory chamber 3A from the inert gas supply device 8, and the atmosphere around the glass fiber G1 passing through the preparatory chamber 3A is replaced with the inert gas. For example, by using the inert gas to positively pressurize the preparatory chamber 3A, it is possible to suppress the atmosphere drawn by the glass fiber G1 from flowing into the preparatory chamber 3A.

[0118] The glass fiber G1 that has passed through the upper portion of the preliminary chamber 3A continuously passes through the cooling device 4. The preliminary chamber 3A is provided in a manner covering the entire cooling device 4, so that the glass fiber G1 passes through the cooling device 4 without being exposed to the atmosphere. Hydrogen is supplied from the hydrogen supply device 9 to the cooling device 4, and the glass fiber G1 that has passed through the cooling device 4 is cooled by the hydrogen.

[0119] The glass fiber G1 that has passed through the cooling device 4 passes through the preparatory chamber 3A again. Since the inert gas is supplied to the preparatory chamber 3A from the inert gas supply device 8, the hydrogen pulled by the glass fiber G1 drawn out from the second opening 42 of the cooling device 4 is replaced by the inert gas. For example, by using the inert gas to positively pressurize the preparatory chamber 3A, it is possible to suppress the hydrogen pulled by the glass fiber G1 from flowing out of the cooling device 4. The hydrogen is diluted by the inert gas in the cooling device 4, and then diluted by the inert gas in the preparatory chamber 3A, and then discharged from the first opening 31A or the second opening 32A. Since the hydrogen is fully diluted by the inert gas and discharged from the preparatory chamber 3A, it will not mix with the atmosphere and explode.

[0120] According to the optical fiber manufacturing apparatus 1B involved in Modification 2, when the cooling device 4 is double-framed, the outer frame can be used as the preliminary chamber 3A. In addition, since the lower end of the cooling device 4 is also covered by the preliminary chamber 3A, the hydrogen gas drawn by the glass fiber G1 drawn out from the cooling device 4 can be replaced with an inert gas.

[0121] (Variant 3)

[0122] Figure 5 FIG. 1 shows a configuration example of an optical fiber manufacturing apparatus 1C according to Modification 3. The optical fiber manufacturing apparatus 1C according to Modification 3 has: Figure 2 The optical fiber manufacturing apparatus 1 shown has an additional structure of an oxygen concentration meter 11. For the sake of convenience, the description of the components having the same reference numerals as those already described in the description of the first embodiment will be omitted.

[0123] like Figure 5 As shown, the optical fiber manufacturing device 1C according to the modification 3 is provided with an oxygen concentration meter 11 in the preparatory chamber 3. The oxygen concentration meter 11 is configured to measure the oxygen concentration in the preparatory chamber 3. The hydrogen supply device 9 is configured to stop supplying hydrogen to the cooling device 4 when the measured value of the oxygen concentration measured by the oxygen concentration meter 11 exceeds a predetermined value.

[0124] Specifically, the oxygen concentration meter 11 outputs information of the measured oxygen concentration value to the control device 10. When the control device 10 determines that the oxygen concentration value in the spare chamber 3 obtained by the oxygen concentration meter 11 exceeds a predetermined value, the control device 10 outputs a control signal to the hydrogen supply device 9 to stop supplying hydrogen to the cooling device 4. The hydrogen supply device 9 stops supplying hydrogen to the cooling device 4 based on the control signal.

[0125] According to the optical fiber manufacturing apparatus 1C according to the third modification, by measuring the oxygen concentration in the preliminary chamber 3 , it is possible to confirm the effect of replacing the air (oxygen) in the preliminary chamber 3 with the inert gas.

[0126] Furthermore, even when the oxygen concentration in the spare room 3 increases, by stopping the supply of hydrogen gas into the cooling device 4 , it is possible to prevent the explosion of hydrogen gas caused by the inflow of atmospheric air into the cooling device 4 .

[0127] [Second embodiment]

[0128] Next, use Figure 6 An optical fiber manufacturing apparatus 1D according to the second embodiment will be described. For the sake of convenience, descriptions of components having the same reference numerals as those already described in the first embodiment will be omitted.

[0129] Figure 6 A configuration example of an optical fiber manufacturing apparatus 1D according to the second embodiment is shown. Figure 7 The structure of a cooling device 4A of an optical fiber manufacturing apparatus 1D is shown.

[0130] like Figure 6 As shown, the optical fiber manufacturing device 1D includes a drawing furnace 2, a cooling device 4A, a resin coating device 5, a resin curing device 6, a winding device 7, an inert gas supply device 8, a hydrogen supply device 9, a control device 10 and a hydrogen recovery device 12.

[0131] The glass fiber G1 drawn from the drawing furnace 2 passes through the cooling device 4A. Hydrogen is supplied to the cooling device 4A from the hydrogen supply device 9 via the gas pipe 91. The glass fiber G1 is cooled by the hydrogen while passing through the cooling device 4A. In addition, inert gas is supplied to the cooling device 4A from the inert gas supply device 8 via the gas pipe 82. The inside of the cooling device 4A is pressurized by the inert gas.

[0132] like Figure 7 As shown, a gas recovery port 46 for recovering hydrogen is provided on the side of the lower part of the cooling device 4A. One end of the gas piping 121 is connected to the gas recovery port 46. The other end of the gas piping 121 is connected to the hydrogen recovery device 12 (see Figure 6). The mixed gas containing hydrogen and inert gas supplied to the cooling device 4A is sucked from the gas recovery port 46 and recovered to the hydrogen recovery device 12. In this example, the gas recovery port 46a and the gas recovery port 46b are arranged at opposite positions, and the mixed gas sucked from the gas recovery port 46a and the gas recovery port 46b is recovered to the hydrogen recovery device 12 through the gas piping 121a and the gas piping 121b. It should be noted that in Figure 6 In the figure, a part of the gas piping 121b is omitted, but the gas piping 121b is connected to the hydrogen recovery device 12. In addition, in this example, the gas piping 121a and the gas piping 121b extend to the inner side of the gas recovery port 46a and the gas recovery port 46b, and the hydrogen is recovered at a position closer to the glass fiber G1.

[0133] In the optical fiber manufacturing method using such an optical fiber manufacturing apparatus 1D, first, the optical fiber preform G is heated and melted in the drawing furnace 2 and drawn (drawing step).

[0134] The glass fiber G1 drawn from the drawing furnace 2 continuously passes through the cooling device 4A. Hydrogen is supplied from the hydrogen supply device 9 to the cooling device 4A, and the glass fiber G1 passing through the cooling device 4A is cooled by the hydrogen (cooling process). In this example, the hydrogen is cooled by the cooling solvent flowing in the cooling passage 45, and the glass fiber G1 passing through the cooling device 4A is cooled by the cooled hydrogen.

[0135] In addition, by supplying inert gas from the inert gas supply device 8 into the cooling device 4A, the inert gas can be used to positively pressurize the cooling device 4A, thereby preventing the atmosphere drawn by the glass fiber G1 from flowing into the cooling device 4A.

[0136] At the lower portion of the cooling device 4A, a mixed gas containing hydrogen and inert gas in the cooling device 4A is sucked from the gas recovery port 46 , and the sucked mixed gas is recovered by the hydrogen recovery device 12 through the gas pipe 121 (recovery step).

[0137] According to the optical fiber manufacturing device 1D and the optical fiber manufacturing method involved in the second embodiment, since hydrogen gas is recovered in front of the second opening 42 of the cooling device 4A, the hydrogen gas pulled by the glass fiber G1 running in the cooling device 4A can be suppressed from flowing out of the cooling device 4A.

[0138] It should be noted that the hydrogen recovery device 12 can also be configured to separate and purify hydrogen from the mixed gas sucked by the gas recovery port 46, so that the hydrogen is regenerated to a state that can be reused. In addition, it can also be configured to connect the hydrogen recovery device 12 and the hydrogen supply device 9 by using a pipe (omitted from the figure) to supply the hydrogen regenerated by the hydrogen recovery device 12 to the hydrogen supply device 9.

[0139] (Variant 4)

[0140] In the above-mentioned second embodiment, the optical fiber manufacturing apparatus 1D may be configured to have one or more preparatory chambers 3 disposed on the upper end of the cooling device 4A, as in the optical fiber manufacturing apparatus 1 according to the first embodiment.

[0141] Figure 8 FIG. 1 shows a configuration example of an optical fiber manufacturing apparatus 1E according to Modification 4. The optical fiber manufacturing apparatus 1E according to Modification 4 has Figure 7 The optical fiber manufacturing apparatus 1D shown has an additional structure of a preparatory chamber 3. For the sake of convenience, descriptions of components having the same reference numerals as those already described in the first and second embodiments are omitted.

[0142] like Figure 8 As shown, the optical fiber manufacturing device 1E is provided with a preparatory chamber 3 provided at the upper end of the cooling device 4A. The preparatory chamber 3 is arranged at the upper end of the cooling device 4A in a state of contacting with the upper end of the cooling device 4A. A first opening 31 for introducing the glass fiber G1 is provided at the upper end of the preparatory chamber 3. A second opening 32 for leading out the glass fiber G1 is provided at the lower end of the preparatory chamber 3. The drawn glass fiber G1 enters the preparatory chamber 3 from the first opening 31, passes through the preparatory chamber 3, and is led out from the second opening 32.

[0143] A gas supply port 33 for supplying an inert gas is provided on the side of the preparatory chamber 3. The inert gas is, for example, argon gas or nitrogen gas. One end of a gas pipe 81 is connected to the gas supply port 33. The other end of the gas pipe 81 is connected to an inert gas supply device 8 (see Figure 6 The inert gas supplied from the inert gas supply device 8 is supplied into the preparatory chamber 3 from the gas supply port 33 through the gas pipe 81 .

[0144] The glass fiber G1 drawn from the drawing furnace 2 continuously passes through the preparatory chamber 3 before passing through the cooling device 4A. An inert gas is supplied from the inert gas supply device 8 to the preparatory chamber 3, and the atmosphere around the glass fiber G1 passing through the preparatory chamber 3 is replaced with the inert gas (replacement process). For example, by using the inert gas to positively pressurize the preparatory chamber 3 of the cooling device 4A, it is possible to suppress the atmosphere drawn by the glass fiber G1 from flowing into the preparatory chamber 3.

[0145] The glass fiber G1 that has passed through the preliminary chamber 3 continuously passes through the cooling device 4A. Since the cooling device 4A is disposed at the lower end of the preliminary chamber 3, the glass fiber G1 that has passed through the preliminary chamber 3 is not exposed to the atmosphere, but is introduced into the cooling device 4A. Hydrogen is supplied from the hydrogen supply device 9 to the cooling device 4A, and the glass fiber G1 that has passed through the cooling device 4A is cooled by the hydrogen (cooling process). In this example, the hydrogen is cooled by the cooling solvent that flows in the cooling passage 45, and the glass fiber G1 that has passed through the cooling device 4A is cooled by the cooled hydrogen.

[0146] According to the manufacturing apparatus 1E and the manufacturing method of the optical fiber according to the fourth modification, since the glass fiber G1 passes through the preliminary chamber 3 to which the inert gas is supplied immediately before entering the cooling device 4A, the atmosphere drawn by the glass fiber G1 traveling at a high speed and entangled around the glass fiber G1 is replaced with the inert gas in the preliminary chamber 3. Thus, it is possible to suppress the inflow of the atmosphere into the cooling device 4A that uses hydrogen gas for cooling.

[0147] (Variant 5)

[0148] In the above-mentioned modification 4, the preliminary chamber 3 is provided only at the upper end of the cooling device 4A, but the preliminary chamber 3 may be provided to cover the entire cooling device 4A including the side and lower end of the cooling device 4A in addition to the upper end of the cooling device 4A.

[0149] Fig. 9 FIG. 1 shows a configuration example of an optical fiber manufacturing apparatus 1F according to Modification 5. Figure 8 Compared with the optical fiber manufacturing apparatus 1E shown, the structure of the preliminary chamber 3 is different. For the components having the same reference numerals as those already described in the above-mentioned modification 2 and modification 4, the description thereof is omitted for the sake of convenience.

[0150] like Fig. 9 As shown, an optical fiber manufacturing apparatus 1F according to Modification 5 includes a preliminary chamber 3A configured to cover the entire cooling device 4A.

[0151] A first opening 31A for introducing the glass fiber G1 is provided at the upper end of the preparatory chamber 3A. A second opening 32A for leading out the glass fiber G1 is provided at the lower end of the preparatory chamber 3A. A gas supply port 33A for supplying an inert gas is provided on the side of the preparatory chamber 3A. One end of the gas pipe 81 is connected to the gas supply port 33A. The other end of the gas pipe 81 is connected to the inert gas supply device 8 (see Figure 6 The inert gas supplied from the inert gas supply device 8 is supplied from the gas supply port 33A into the preparatory chamber 3A through the gas pipe 81 .

[0152] The glass fiber G1 drawn from the drawing furnace 2 enters the preparatory chamber 3A before passing through the cooling device 4A. The inert gas is supplied to the preparatory chamber 3A from the inert gas supply device 8, and the atmosphere around the glass fiber G1 passing through the upper part of the preparatory chamber 3A is replaced with the inert gas. For example, by using the inert gas to make the preparatory chamber 3 positively pressurized, it is possible to suppress the atmosphere drawn by the glass fiber G1 from flowing into the preparatory chamber 3.

[0153] The glass fiber G1 that has passed through the upper part of the preliminary chamber 3A continuously passes through the cooling device 4A. The preliminary chamber 3 is provided in a manner covering the entire cooling device 4A, so that the glass fiber G1 passes through the cooling device 4A without being exposed to the atmosphere. Hydrogen is supplied to the cooling device 4A from the hydrogen supply device 9, and the glass fiber G1 that passes through the cooling device 4A is cooled by the hydrogen.

[0154] The glass fiber G1 that has passed through the cooling device 4A passes through the preparatory chamber 3A again. Since the inert gas is supplied to the preparatory chamber 3A from the inert gas supply device 8, the hydrogen gas drawn by the glass fiber G1 drawn out from the second opening 42 of the cooling device 4A is replaced by the inert gas. For example, by making the preparatory chamber 3A positively pressurized with the inert gas, the hydrogen gas drawn by the glass fiber G1 can be suppressed from flowing out of the cooling device 4A.

[0155] According to the optical fiber manufacturing device 1F involved in Modification 5, when the cooling device 4A is double-framed, the outer frame can be used as the preliminary chamber 3A. In addition, since the lower end of the cooling device 4A is also covered by the preliminary chamber 3A, the hydrogen gas drawn by the glass fiber G1 drawn out from the second opening 42 of the cooling device 4A can be replaced with an inert gas.

[0156] The present disclosure is described in detail and with reference to specific embodiments, but it is obvious 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. In addition, the number, position, shape, etc. of the components described above are not limited to the above embodiments, and can be changed to appropriate numbers, positions, shapes, etc. when implementing the present disclosure.

[0157] Description of Reference Numerals

[0158] 1: Optical fiber manufacturing device; 1A: Optical fiber manufacturing device; 1B: Optical fiber manufacturing device; 1C: Optical fiber manufacturing device; 1D: Optical fiber manufacturing device; 1E: Optical fiber manufacturing device; 1F: Optical fiber manufacturing device; 2: Wire drawing furnace; 3: Preparation chamber; 3a: Preparation chamber; 3A: Preparation chamber; 3b: Preparation chamber; 4: Cooling device; 4A: Cooling device; 5: Resin coating device; 6: Resin curing device; 7: Winding device; 8: Inert gas supply device; 9: Hydrogen supply device; 10: Control device; 11: Oxygen concentration meter; 12: Hydrogen recovery device; 21: Furnace core tube; 22: Heater; 31: First opening; 31a: First opening; 31A: First opening; 31b: First opening; 32: Second opening; 32a: Second opening : opening; 32A: second opening; 32b: second opening; 33: gas supply port; 33a: gas supply port; 33A: gas supply port; 33b: gas supply port; 41: first opening; 42: second opening; 43: gas supply port; 44: gas supply port; 44a: gas supply port; 44b: gas supply port; 45: cooling passage; 46: gas recovery port; 46a: gas recovery port; 46b: gas recovery port; 81: gas piping; 81a: gas piping; 81b: gas piping; 82: gas piping; 91: gas piping; 91a: gas piping; 91b: gas piping; 121: gas piping; 121a: gas piping; 121b: gas piping; G: optical fiber base material; G1: glass fiber; G2: optical fiber.

Claims

1. An optical fiber manufacturing device, comprising: Wire drawing furnace, heating and melting the optical fiber mother material and drawing; A cooling device is used to cool the drawn glass fibers; A preparatory chamber, arranged at the upper end of the cooling device; a hydrogen supply device for supplying hydrogen into the cooling device; and The inert gas supply device supplies the inert gas into the preparation chamber.

2. The optical fiber manufacturing device according to claim 1, The manufacturing device includes a plurality of the preparatory chambers stacked on an upper end of the cooling device, The inert gas supply device is configured to supply the inert gas to each of the plurality of preliminary chambers.

3. The optical fiber manufacturing device according to claim 1 or 2, The manufacturing apparatus includes an oxygen concentration meter for measuring the oxygen concentration in the preliminary chamber.

4. The optical fiber manufacturing device according to claim 3, The hydrogen gas supply device stops supplying hydrogen gas to the cooling device when the value of the oxygen concentration measured by the oxygen concentration meter exceeds a predetermined value.

5. The optical fiber manufacturing device according to claim 1 or 2, The preliminary chamber is configured to cover the entire cooling device.

6. An optical fiber manufacturing device, comprising: Wire drawing furnace, heating and melting the optical fiber mother material and drawing; A cooling device is used to cool the drawn glass fibers; a hydrogen supply device for supplying hydrogen into the cooling device; and A hydrogen recovery device recovers the hydrogen supplied to the cooling device, A hydrogen recovery port for recovering the hydrogen in the cooling device is provided at the lower part of the cooling device.

7. The optical fiber manufacturing device according to claim 6, comprising: a preparatory chamber, disposed at an upper end of the cooling device; and The inert gas supply device supplies the inert gas into the preparation chamber.

8. The optical fiber manufacturing device according to claim 7, The preliminary chamber is configured to cover the entire cooling device.

9. A method for manufacturing an optical fiber, comprising: The drawing process is to heat and melt the optical fiber mother material and then draw it; a cooling step of cooling the drawn glass fiber by passing the drawn glass fiber through a cooling device supplied with hydrogen; as well as The replacement step is to replace the atmosphere around the glass fiber with the inert gas by passing the glass fiber through a preliminary chamber disposed at an upper end of the cooling device and supplied with the inert gas before the cooling step.

10. A method for manufacturing an optical fiber, comprising: The drawing process is to heat and melt the optical fiber mother material and then draw it; a cooling step of cooling the drawn glass fiber by passing the drawn glass fiber through a cooling device supplied with hydrogen; as well as The recovery step is to recover the hydrogen gas in the cooling device at a lower portion of the cooling device.

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