KR20100094749A - Apparatus for cooling optical fiber used in optical fiber drawing process and, methods for cooling optical fiber - Google Patents

Abstract

PURPOSE: An optical fiber cooling apparatus for an optical fiber drawing process, and a method thereof are provided to uniformly coat an optical fiber by controlling the supply quantity of a refrigerant. CONSTITUTION: An optical fiber cooling apparatus for an optical fiber drawing process comprises the following: a cooling pipe(30) cooling an optical fiber(20); a feeder supplying a refrigerant to cool the optical fiber, to the cooling pipe; a collecting unit collecting the refrigerant from the cooling pipe and supplying to the feeder; an external-diameter measuring unit(40); and a controller(50) controlling the collecting amount of refrigerant.

Description

Apparatus for cooling optical fiber used in optical fiber drawing process and, methods for cooling optical fiber

The present invention relates to an optical fiber cooling apparatus and a method thereof, and more particularly, by measuring an outer diameter of a coated optical fiber that more accurately informs the coating state of the optical fiber in the drawing process of the optical fiber, thereby controlling the supply and regeneration of the refrigerant. The coating is made uniform, and even if the supply amount of the coolant is small, the amount of the coolant can be reduced by increasing the regeneration amount of the coolant used for cooling, and because the configuration is simple, the optical fiber cooling device can reduce the installation cost and It's about how.

In general, the optical fiber manufacturing process is a base material manufacturing process for manufacturing an optical fiber base material using MCVD, OVD, VAD method, and the like, and the manufactured optical fiber base material is melted using a high temperature furnace (furnace) and thin (outer diameter of about 125 Μm) It can be divided into optical fiber drawing process to draw optical fiber. In order to improve the price competitiveness of optical fibers, optical fiber manufacturers are seeking to increase the size of the base metal by improving the base material manufacturing process, and to increase the speed of optical fiber drawing by improving the fiber drawing process.

The optical fiber drawing process includes the steps of melting and extracting the optical fiber base material, cooling the optical fiber drawn down, coating the cooled optical fiber, curing the optical fiber coating through UV irradiation, and finally spool It is divided into winding stages.

Among these, the step of cooling the optical fiber is an essential step required to reduce the melted and extracted high temperature optical fiber to a temperature at which coating is possible (below 100 ° C.). In the case of inadequate cooling, the coating thickness becomes thin, Bubbles in the coating, slippage of the coating liquid (slip) due to the problem that the tensile strength (bare fiber tesion) of the optical fiber or fiber is sharply different than when the cooling is performed under normal cooling conditions.

Among the factors that determine the cooling level, the drawing speed of the optical fiber is important. When drawing at a high speed, cooling is relatively insufficient, and when drawing at a low speed, cooling is relatively stable.

In other words, in order to secure price competitiveness through high speed of drawing, a cooling technology capable of sufficiently cooling even at a high drawing speed is essential. For this purpose, an artificial cooling system is used under high speed drawing conditions.

The artificial cooling system allows the molten optical fiber to pass through the cooling tube and supplies a coolant inside the cooling tube to cool the optical fiber. The coolant takes heat from the optical fiber and transfers it to the cooling tube, and the heat transferred to the cooling tube is transferred to the air or the cooling water flowing through the cooling tube, thereby cooling.

Helium gas is widely used as the refrigerant used in the cooling tube because the thermal conductivity of the helium gas is excellent and the optical fiber can be efficiently cooled.

However, since the price of helium gas is high, it is a factor that deteriorates the price competitiveness of the optical fiber.

In order to solve this problem, a cooling device capable of reusing a refrigerant discharged after cooling an optical fiber in a cooling tube has been proposed. US patent US 5,377,491 (hereinafter referred to as 'prior art 1') discloses such a cooling device.

As shown in Figure 1, the prior art 1 forcibly moves the refrigerant discharged from the heat exchanger (1) to the regeneration vessel (7) by using a compressor (5), the regeneration vessel ( The refrigerant of 7) and the refrigerant of the refrigerant storage tank 8 are combined and supplied to the heat exchanger 1.

The refrigerant discharged from the heat exchanger 1 passes through the control member 1a and the measuring member 2a. The control member 1a controls the flow of the refrigerant flowing out of the heat exchanger 1 and / or flowing into the heat exchanger 1. The measuring member 2a measures and transmits the flow rate of the refrigerant discharged from the heat exchanger 1, measures the concentration of impurity contained in the refrigerant discharged from the heat exchanger 1, and measures the pressure of the refrigerant. do. The operating amount of the compressor 5 and the refrigerant storage tank 8 according to the flow rate of the refrigerant measured by the measuring member 2a, the concentration of impurities, and the pressure measured by the measuring member 2a and the pressure gauge 3. The amount of coolant supplied from is determined. On the other hand, reference numeral 4 denotes a cooling means for cooling the refrigerant.

As described above, the prior art 1 includes means for monitoring the state of the refrigerant (pressure, concentration of impurities, flow rate, pressure) and valves for controlling the means in various sections to adjust the state of the refrigerant. Prior art 1 has the advantage of reducing the cost of the refrigerant because some of the refrigerant can be reused.

However, the prior art 1 has a problem in that the configuration of the apparatus is complicated and the installation cost of the control member 1a, the measuring member 2a, and various valves is high. In addition, the prior art 1 does not directly monitor the cooling state of the optical fiber to regulate the supply of the refrigerant, but rather monitors the refrigerant state (concentration of impurities contained in the refrigerant, measured by the measuring member 2a, etc.) of the refrigerant. Due to the regulation of the supply, there is a limit to achieving accurate cooling.

On the other hand, Figure 2 shows the main configuration of another cooling device. The cooling device is disclosed in US Pat. No. 6,648,946 (hereinafter referred to as Prior Art 2).

The prior art 2 has a helium gas heat exchanger (15) via a control valve (11), a particulate filter (12), an eductor (13) and a cooler (14). After supplying to the optical fiber to cool the optical fiber and the like, part of the helium gas is recovered by the suction force of the eductor 13 and the other part is discharged to the outside. That is, some of the helium gas is moved to the eductor 13 via the filter 16 by the suction force of the eductor 13, mixed with the helium gas supplied through the particle filter 12, and then cooler 14 Is supplied to the heat exchanger (15) via. The eductor 13 has a venturi structure, and the helium of the heat exchanger 15 is caused by the suction force generated because helium gas passing through the particle filter 12 passes through the eductor 13 at a high speed. The gas is inhaled.

As described above, the prior art 2 implements the refrigerant regeneration by fluid flow using the eductor 13 rather than the forced regeneration method using the compressor 5 (prior art 1). Compared to the prior art 1, the prior art 2 has the advantage that the installation cost is low because the refrigerant can be regenerated without additional equipment such as the measuring member 2a, the control member 1a, and the pressure gauge 3, and the like.

However, in the prior art 2, when the refrigerant supply amount decreases because the suction force for determining the refrigerant recovery amount is determined by the refrigerant supply amount (amount of helium gas supplied to the eductor 13 via the particle filter 12). The problem that the amount of refrigerant regeneration is also reduced. Therefore, when the amount of refrigerant supplied is reduced, the amount of refrigerant regeneration is also reduced, resulting in a problem that the cooling performance is drastically lowered.

The present invention is to measure the outer diameter of the coated optical fiber that more accurately informs the coating state of the optical fiber in the drawing process of the optical fiber to adjust the amount of supply and regeneration of the refrigerant to make the coating of the optical fiber uniformly, and the method The purpose is to provide.

Still another object of the present invention is to provide an optical fiber cooling apparatus and a method thereof, which can reduce the amount of refrigerant used by increasing the amount of refrigerant used for cooling even if the supply amount of refrigerant is small.

It is still another object of the present invention to provide an optical fiber cooling apparatus and method which can reduce the installation cost because of its simple configuration.

In order to achieve the above object, an optical fiber cooling device according to the present invention comprises: a cooling tube in which a drawn optical fiber is cooled while passing therein; A supply unit for supplying a refrigerant supplied from a storage tank and a refrigerant recovered by a recovery unit to a cooling tube to cool the optical fiber passing through the inside; A recovery unit installed to connect a cooling tube and a supply unit to recover a coolant after cooling the optical fiber in the cooling tube and to supply the supply unit to the supply unit; An outer diameter measuring unit measuring an outer diameter of the coated optical fiber after being cooled while passing through a cooling tube; And a controller configured to adjust the amount of the refrigerant supplied from the storage tank and the amount of the refrigerant recovered by the recovery unit according to the outer diameter measured by the outer diameter measuring unit.

Preferably, the controller compares the outer diameter with a reference value to increase the amount of refrigerant supplied from the storage tank when the outer diameter is smaller than the reference value, and decrease the amount of refrigerant supplied from the storage tank when the outer diameter is larger than the reference value.

Here, the controller compares the outer diameter with a reference value to increase the amount of refrigerant recovered by the recovery unit when the outer diameter is smaller than the reference value, and decrease the amount of refrigerant recovered by the recovery unit when the outer diameter is larger than the reference value. It is preferable.

Preferably, the supply unit is connected to the storage tank flow rate control member for controlling the amount of refrigerant discharged from the storage tank; And a cooling member for cooling the refrigerant moved from the storage tank and the refrigerant recovered by the recovery unit.

Here, the recovery unit includes a recovery member for moving the refrigerant inside the cooling tube to the supply unit, and the amount of the refrigerant moved by the recovery member is preferably controlled by the control unit.

According to another aspect of the present invention, a method of cooling an optical fiber includes allowing the drawn optical fiber to pass through a cooling tube so that the optical fiber is cooled by a refrigerant; Supplying the refrigerant moved from the storage tank and the refrigerant recovered from the cooling tube to the cooling tube; Measuring the outer diameter of the coated optical fiber after being cooled while passing through a cooling tube; And comparing the outer diameter with a reference value to adjust an amount of the refrigerant supplied from the storage tank and an amount of the refrigerant recovered from the cooling tube.

Preferably, when the outer diameter is smaller than the reference value, the amount of the coolant supplied from the storage tank is increased when the outer diameter is smaller than the reference value, and the amount of the coolant supplied from the storage tank is increased when the outer diameter is larger than the reference value.

Here, when the outer diameter is smaller than the reference value by comparing the outer diameter with the reference value, the amount of the refrigerant recovered by the recovery unit is increased, but the amount of the recovered refrigerant is smaller than a predetermined amount, and when the outer diameter is larger than the reference value, It is desirable to reduce the amount of refrigerant recovered by the recovery section.

According to the present invention, an optical fiber cooling apparatus and method used in an optical fiber drawing process have the following effects.

First, in the drawing process of the optical fiber to measure the outer diameter of the coated optical fiber that more accurately informs the coating state of the optical fiber to adjust the amount of supply and regeneration of the refrigerant to ensure uniform coating of the optical fiber.

Second, even if the supply amount of the refrigerant is small, it is possible to reduce the amount of refrigerant used by increasing the regeneration amount of the refrigerant used for cooling.

Third, the installation cost can be reduced because of the simple configuration.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely examples of the present invention and are not intended to represent all of the technical ideas of the present invention, so that various equivalents And variations are possible.

In general, the outer diameter (hereinafter referred to as 'outer diameter') of the coated optical fiber is determined by the cooling state of the optical fiber, and the cooling state is determined by the flow rate of the refrigerant and the drawing flux of the optical fiber. The outer diameter is inversely proportional to the drawing flux (the flux of the optical fiber).

The optical fiber cooling apparatus according to the present invention cools the optical fiber drawn in the optical fiber drawing process by using a coolant, and measures the outer diameter of the coated optical fiber to control the supply amount of the coolant and the amount of the recovered coolant (regeneration amount). .

3 is a block diagram showing an optical fiber cooling apparatus according to a preferred embodiment of the present invention.

Referring to the drawings, the optical fiber cooling apparatus 100 includes a cooling tube 30 for cooling the drawn optical fiber 20, a supply unit for supplying a refrigerant to the cooling tube 30, a cooling tube 30, and a supply unit. It is installed so as to connect the recovery unit for recovering the refrigerant after cooling the optical fiber 20 in the cooling tube 30 to supply to the supply unit, and cooled through the cooling tube 30 and the outer diameter of the coated optical fiber 20 The outer diameter measuring unit 40 to measure, and the controller 50 for adjusting the amount of the coolant supplied to the cooling tube 30 according to the outer diameter measured by the outer diameter measuring unit 40.

The cooling tube 30 has a hollow portion formed in the longitudinal direction. The drawn optical fiber 20 is cooled by the refrigerant while moving through the hollow part. The supply pipe 69 and the recovery pipe 71 are connected to the hollow portion. The coolant is supplied through the supply pipe 69, and the coolant after cooling the optical fiber 20 is discharged to the outside or moved to the filter member 72 through the recovery pipe 71.

The supply unit supplies the cooling tube 30 with the refrigerant supplied from the storage tank 61 and the refrigerant recovered by the recovery unit to cool the optical fiber 20 passing through the inside of the cooling tube 30.

The supply part has a flow rate control member 62 connected to the storage tank 61, a cooling member 63 for cooling the refrigerant via the flow rate control member 62 and the refrigerant recovered by the recovery unit, and a cooling member 63. It includes a first flow meter 64 for measuring the flow rate of the refrigerant via the.

The storage tank 61 is a tank for storing the refrigerant. Helium gas, nitrogen gas, hydrogen gas, carbon dioxide gas, etc. may be used as the refrigerant. The flow rate control member 62 adjusts the flow rate of the refrigerant discharged from the storage tank 61 under the control of the control unit 50. A solenoid valve or the like may be used as the flow control member 62. The refrigerant passing through the flow control member 62 is moved to the cooling member 63 together with the refrigerant recovered by the recovery unit.

The cooling member 63 is a member for cooling the refrigerant and has the same structure as the cooling means 4 of the prior art 1 or the cooler 14 of the prior art 2.

The first flow meter 64 measures the flow rate of the refrigerant supplied to the cooling tube 30. As the first flow meter 64, a conventional flow measuring device may be used.

The recovery unit is installed to connect the cooling tube 30 and the supply unit to recover the refrigerant after cooling the optical fiber 20 in the cooling tube 30 to move to the supply unit. The recovery unit includes a filter member 72 connected to the recovery tube 71 so as to remove foreign substances contained in the refrigerant recovered from the cooling tube 30, a second flow meter 73 measuring a flow rate of the recovered refrigerant; A recovery member 75 for moving the refrigerant via the filter member 72 to the supply unit, and a control valve 74 for controlling the amount of the refrigerant to be recovered.

The filter member 72 removes particles and the like contained in the recovered refrigerant, and the second flow meter 73 measures the flow rate of the refrigerant passing through the filter member 72.

The recovery member 75 generates a suction force to forcibly suck the refrigerant inside the cooling tube 30. As the recovery member 75, a vacuum pump or a compressor may be used.

The control valve 74 is a valve in which the degree of opening and closing is controlled by the control of the control unit 50. For example, when the outer diameter of the coated optical fiber 20 is smaller than the reference value, the opening of the control valve 74 is increased to increase the amount of refrigerant to be regenerated, and when the outer diameter of the coated optical fiber 20 is larger than the reference value, the control valve ( The opening of 74) is made small so that the amount of refrigerant to be recycled is made small. On the other hand, when the suction force exceeds a predetermined level and the amount of the refrigerant to be recycled is excessive, since the amount of external gas flowing into the cooling tube 30 increases, the cooling state of the optical fiber 20 becomes poor and the coated optical fiber 20 is applied. The outer diameter of may be rather small, which is explained below.

A chamber 76 having a predetermined size is preferably installed at the rear of the recovery member 75. The chamber 76 reduces the pressure fluctuation of the refrigerant passing through the recovery member 75, and the flow of the refrigerant. Make it easy to control. The refrigerant via the chamber 76 is mixed with the refrigerant supplied from the storage tank 61 and then moved to the cooling member 63.

Meanwhile, the optical fiber 20 cooled while passing through the cooling tube 30 is coated by the coating member 80. Since the coating member 80 has a conventional structure, a detailed description thereof will be omitted. The optical fiber 20 via the coating member 80 is moved to the outer diameter measuring unit 40.

The outer diameter measuring unit 40 measures the outer diameter of the coated optical fiber 20, and transmits the measured outer diameter data to the controller 50. A conventional apparatus for measuring the outer diameter of the optical fiber 20 is provided in the outer diameter measuring unit 50.

The controller 50 adjusts the amount of the coolant supplied from the storage tank 61 and the amount of the coolant recovered by the recovery unit according to the outer diameter measured by the outer diameter measuring unit 40 so that an appropriate coating is performed.

For example, the controller 50 increases the amount of the refrigerant supplied from the storage tank 61 by adjusting the flow control member 62 when the measured outer diameter is smaller than the reference value. As an alternative to increasing the amount of refrigerant supplied from the storage tank 61, the controller 50 may increase the amount of refrigerant recovered by adjusting the control valve 74. As an alternative to the above two methods, both the amount of refrigerant supplied from the storage tank 61 and the amount (regeneration amount) of the refrigerant recovered may be increased.

When the amount of the refrigerant supplied from the storage tank 61 is increased or the amount of the refrigerant recovered is increased, the cooling speed of the optical fiber 20 is effectively cooled because the moving speed of the refrigerant is increased in the cooling tube 30. On the other hand, if the amount of the recovered refrigerant exceeds a predetermined amount (upper limit), the outside air is introduced into the cooling tube 30 is not effective for cooling.

That is, as shown in Figure 4, as the amount of the refrigerant supplied from the storage tank 61 (described as 'intake amount' in Figure 4) increases, the cooling of the optical fiber 20 is effectively made and coated optical fiber ( Although the outer diameter of 20) is also increased, it is not desirable to increase the amount of infinity indefinitely due to the cost of the refrigerant, and it is preferable to recover and use the refrigerant. On the other hand, the outer diameter increases until the amount of the refrigerant to be recovered (described as 'regeneration amount' in FIG. 4) becomes a predetermined amount, i.e., the upper limit, but the outer diameter decreases when the amount of the recycled amount exceeds the upper limit. This is because the cooling effect increases because the moving speed of the coolant in the cooling pipe 30 increases to the upper limit until the upper limit exceeds the upper limit, so that the coolant is not effectively cooled because the inflow of external air increases. . Referring to FIG. 4, it can be seen that the upper limit value is a case where the regeneration amount is three times or more and four times or less, and the upper limit value may vary depending on the specific structure of the apparatus 100.

The optimum value of the drawing amount and the regeneration amount is determined by various conditions such as the specific specifications of the apparatus 100, that is, the structure and material of the cooling tube 30, the atmospheric temperature, the cooling water temperature, the drawing temperature, and the flux of the optical fiber 20. do. In order to realize an optimal cooling state and to obtain a uniform outer diameter, it is desirable to have the amount of retraction and the amount of regeneration corresponding to the area (blue area) of FIG. 5. In FIG. 5, the unit of the x-axis and the y-axis is slpm (standard liter per minute).

 On the other hand, if the outer diameter is larger than the reference value, the controller 50 adjusts the flow control member 62 to reduce the amount of refrigerant supplied from the storage tank 61. As an alternative to reducing the amount of refrigerant supplied from the storage tank 61, the controller 50 may reduce the amount of refrigerant recovered by adjusting the control valve 74. As an alternative to the above two methods, both the amount of refrigerant supplied from the storage tank 61 and the amount (regeneration amount) of the refrigerant recovered may be reduced.

Table 1 below shows the relationship between the incoming amount, the recycle amount and the outer diameter in the apparatus 100 according to the present invention.

TABLE 1

Intake quantity (slpm) Regeneration amount (slpm) Outer Diameter (㎛) Cooling state

9 10 235 insufficiency 20 242 enough 30 247 enough 40 250 enough 50 245 enough 60 233 insufficiency

12 10 237 insufficiency 20 244 enough 30 250 enough 40 254 enough 50 253 enough 60 240 enough

15 10 240 enough 20 248 enough 30 254 enough 40 258 enough 50 259 enough 60 258 enough

Table 2 below shows the embodiments performed while adjusting the incoming amount and the regeneration amount when the ship speed is 1500mpm, and Table 3 shows the embodiments performed while adjusting the input amount and the regeneration amount when the ship speed is 1600mpm.

TABLE 2

Ship speed
[mpm] Outer diameter
[Μm] Intake
[lpm] Regeneration
[lpm] Total refrigerant amount
[lpm] Remarks standard 1500 250 10 15 25 Example 1 1500 251 → 250 10 → 9 15 25 → 24 Reduces the amount of incoming so that the outer diameter is 250㎛ Example 2 1500 249 → 250 10 15 → 17 25 → 27 Increased regeneration amount to make outer diameter 250㎛

In Example 1, when the cooling condition is increased due to an unspecified cause, the outer diameter is reduced to 9 (lpm, liter per minute) when the outer diameter becomes 251 µm, so that the outer diameter becomes 250 µm. As a result, when the cooling state was reduced and the outer diameter became 249 µm, the regeneration amount was increased to 17 (lpm) so that the outer diameter became 250 µm.

TABLE 3

Ship speed
[mpm] Outer diameter
[Μm] Intake
[lpm] Regeneration
[lpm] Total refrigerant amount
[lpm] Remarks standard 1600 250 10 17 27 Example 3 1600 251 → 250 10 → 9 17 27 → 26 Reduces the amount of incoming so that the outer diameter is 250㎛ Example 4 1600 249 → 250 10 17 → 21 27 → 31 Increased regeneration amount to make outer diameter 250㎛

In Example 3, when the cooling state increased due to an unspecified cause, the outer diameter was reduced to 9 (lpm) when the outer diameter became 251 µm, so that the outer diameter became 250 µm. When the outer diameter was reduced to 249 µm, the regeneration amount was increased to 21 (lpm) so that the outer diameter was 250 µm.

On the other hand, when the optical fiber cooling device 100 according to the present invention can be used to recover the refrigerant can reduce the amount of refrigerant used. That is, since the refrigerant is forcibly sucked using the recovery member 75, the amount of the refrigerant used can be reduced as compared with the prior art 2 using the eductor 13 and the case where the refrigerant is not recovered. Fig. 6 is a graph comparing the amount of helium gas used in the present invention with the prior art 2 when the refrigerant is not recovered (the regeneration apparatus is not used). As shown in FIG. 6, the present invention can reduce the amount of refrigerant used by 60% compared with the case where no refrigerant is recovered, and can reduce the amount of refrigerant used by 33% compared to the prior art 2.

In addition, since the prior art 1 monitors the refrigerant state and predicts the cooling state, facilities such as a control member 1a, a measuring member 2a, various valves, and the like for monitoring and controlling the refrigerant state are required, and the manufacturing cost is high. It takes In contrast, the present invention directly measures the outer diameter of the coated optical fiber 20, and the amount of retraction (the amount of refrigerant supplied from the storage tank 61) and the regeneration amount (the refrigerant recovered from the cooling tube 30 by the recovery unit) The configuration is simple because only the amount of) is controlled. Therefore, the present invention can greatly reduce the manufacturing cost.

In addition, the present invention has a small deviation in the outer diameter since the outer diameter of the coated optical fiber 20 is directly measured to control the flow rate of the refrigerant. In contrast, the prior art 1 has difficulty in implementing accurate cooling because it monitors the state of the refrigerant and predicts the cooling state, and thus there is a problem that the coating state becomes uneven. Figure 7 shows the deviation of the outer diameter in the prior art 1,2 and the present invention. As shown in Figure 7, it can be seen that the deviation in the present invention is only 50% of the prior art 1, 40% of the prior art 2.

On the other hand, the present invention is supplied to the cooling tube 30 after cooling the refrigerant using the cooling member (63). 8 compares the case where the cooling member 63 is provided (improvement) with the case where it is not provided (existing). As shown in FIG. 8, when the cooling member 63 is used, a refrigerant having a constant temperature may be supplied, whereas when the cooling member 63 is not provided, a refrigerant having a different temperature is supplied for each season. .

Then, the operation of the optical fiber cooling device 100 according to the present invention will be described.

First, the refrigerant stored in the storage tank 61 is supplied to the cooling pipe 30 via the flow rate adjusting member 62, the cooling member 63, and the first flow meter 64. At this time, the refrigerant recovered from the cooling tube 30 by the recovery unit is also supplied to the cooling tube 30. The coolant supplied to the cooling tube 30 is discharged to the outside after the optical fiber 20 is cooled or sucked into the recovery tube 71.

The refrigerant moved to the recovery pipe 71 is supplied to the cooling member 63 via the filter member 72, the second flow meter 73, the control valve 74, the recovery member 75, and the chamber 76. . The coolant (regenerated coolant) supplied to the cooling member 63 is cooled together with the coolant (newly supplied coolant) moved from the storage tank 61, and then the cooling pipe 30 is passed through the first flow meter 63. Is fed back to.

Meanwhile, after the optical fiber 20 discharged from the cooling tube 30 is coated, the outer diameter of the optical fiber 20 is measured by the outer diameter measuring unit 40, and the data about the outer diameter is transmitted to the controller 50. When the outer diameter is smaller than the reference value, the control unit 50 adjusts the flow control unit 62 to increase the amount of refrigerant supplied from the storage tank 61, or adjust the control valve 74 to control the cooling pipe 30. ) Or the amount of refrigerant to be supplied from the storage tank 61 and the amount of the refrigerant recovered from the cooling pipe 30 by adjusting the flow control member 62 and the control valve 74 together. Increase both.

If the amount of the coolant supplied from the storage tank 61 is increased, the cooling is sufficiently performed, so that the outer diameter increases, and if the amount of the coolant recovered from the cooling tube 30 is increased, the flow rate of the coolant in the cooling tube 30 is increased. This speeds up, so that cooling is sufficiently performed and the outer diameter is increased. However, when the amount of the refrigerant recovered in the cooling tube 30 exceeds the upper limit, since the external air may be excessively introduced into the cooling tube 30, the cooling effect may be lowered and the outer diameter may be reduced. As shown.

On the other hand, when the outer diameter is larger than the reference value, the controller 50 adjusts the flow control member 62 to reduce the amount of refrigerant supplied from the storage tank 61, or adjust the control valve 74 to control the cooling pipe. The amount of the coolant sucked in the cooling pipe 30 and the amount of the coolant supplied from the storage tank 61 may be reduced by reducing the amount of the coolant sucked in the 30 or by adjusting the flow control member 62 and the control valve 74 together. Reduce both of them. When the amount of the refrigerant supplied from the storage tank 61 is reduced or the amount of the refrigerant recovered in the cooling tube 30 is reduced, the cooling effect of the optical fiber 20 is reduced, so that the outer diameter is reduced.

1 is a block diagram showing an optical fiber cooling device according to the prior art.

Figure 2 is a block diagram showing another optical fiber cooling apparatus according to the prior art.

3 is a block diagram showing an optical fiber cooling apparatus according to a preferred embodiment of the present invention.

4 is a graph showing a relationship between a supply amount of a coolant, a recovery amount of a coolant, and a coated optical fiber outer diameter when the optical fiber cooling device of FIG. 1 is used.

5 shows the range of the preferred amount of drawback and regeneration

6 is a graph comparing the amount of helium gas used in the prior art 2 and the present invention, when the refrigerant is not recovered.

7 is a graph showing the outer diameter deviation of the coated optical fiber in the prior art 1 and the prior art 2 and the present invention.

8 is a graph showing seasonally the temperature of a refrigerant supplied to a cooling tube.

<Explanation of symbols for the main parts of the drawings>

20: optical fiber 30: cooling tube

40: outer diameter measuring unit 50: control unit

61: storage tank 62: flow control material

63 cooling member 64 first flow meter

69 supply pipe 71 recovery pipe

72 filter member 73 second flow meter

74: control valve 75: recovery member

76: chamber 80: coating member

100: optical fiber chiller

Claims (8)

A cooling tube through which the drawn optical fiber is cooled while passing therein; A supply unit for supplying a refrigerant supplied from a storage tank and a refrigerant recovered by a recovery unit to a cooling tube to cool the optical fiber passing through the inside; A recovery unit installed to connect a cooling tube and a supply unit to recover a coolant after cooling the optical fiber in the cooling tube and to supply the supply unit to the supply unit; An outer diameter measuring unit measuring an outer diameter of the coated optical fiber after being cooled while passing through a cooling tube; And And a control unit for adjusting the amount of the refrigerant supplied from the storage tank and the amount of the refrigerant recovered by the recovery unit according to the outer diameter measured by the outer diameter measuring unit. The method of claim 1, The controller compares the outer diameter with a reference value to increase the amount of refrigerant supplied from the storage tank when the outer diameter is smaller than the reference value, and decrease the amount of refrigerant supplied from the storage tank when the outer diameter is larger than the reference value. Fiber optic chiller. The method according to claim 1 or 2, The controller compares the outer diameter with a reference value to increase the amount of refrigerant recovered by the recovery unit when the outer diameter is smaller than the reference value and reduce the amount of refrigerant recovered by the recovery unit when the outer diameter is larger than the reference value. Fiber optic chiller made. The method of claim 1, Supply part, A flow control member connected to the storage tank to adjust an amount of the refrigerant discharged from the storage tank; And And a cooling member for cooling the refrigerant moved from the storage tank and the refrigerant recovered by the recovery unit. The method according to claim 1 or 4, The recovery unit includes a recovery member for moving the refrigerant inside the cooling pipe to the supply unit, and the amount of the refrigerant moved by the recovery member is controlled by the control unit. Allowing the drawn optical fiber to pass through the cooling tube so that the optical fiber is cooled by the refrigerant; Supplying the refrigerant moved from the storage tank and the refrigerant recovered from the cooling tube to the cooling tube; Measuring the outer diameter of the coated optical fiber after being cooled while passing through a cooling tube; And And adjusting the amount of the refrigerant supplied from the storage tank and the amount of the refrigerant recovered from the cooling tube by comparing the outer diameter with a reference value. The method of claim 6, Comparing the outer diameter with a reference value to increase the amount of refrigerant supplied from the storage tank if the outer diameter is smaller than the reference value and increase the amount of refrigerant supplied from the storage tank if the outer diameter is larger than the reference value. . The method according to claim 6 or 7, If the outer diameter is smaller than the reference value by comparing the outer diameter with the reference value, the amount of refrigerant recovered by the recovery unit is increased, but the amount of the recovered refrigerant is smaller than a predetermined amount, and when the outer diameter is larger than the reference value, Reducing the amount of refrigerant recovered by the optical fiber cooling method.

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