MXPA00005602A - Cooler of optical fiber draw tower - Google Patents

Abstract

A cooler of an optical fiber draw tower. The cooler situated below a melting furnace for melting a preform for an optical fiber, for cooling the optical fiber drawn from the preform melted in the melting furnace, includes at least one heat exchanger installed with a predetermined length surrounding the optical fiber drawn from the melting furnace, for cooling the drawn optical fiber. The heat exchanger is formed of a thermo-electric cooler (TEC) for taking electrical energy through one heat absorbing surface to emit heat to the other heat emitting surface and has a tubular shape in which the heat absorbing surface of the TEC surrounds the optical fiber drawn from the melting furnace along the drawing direction by a predetermined length, and the drawn optical fiber is cooled as it passes through the tubular TEC. Also, the cooler further includes an auxiliary cooler attached to the heat emitting surface of the TEC, for cooling the emitted heat. Therefore, the cooler can enhance the cooling effect, so that the drawing of the optical fiber can be sped up without increasing the height of the optical fiber draw tower.

Description

REFRIGERANT FOR FIBER OPTIC REMOVING TOWER TECHNICAL FIELD The present invention relates to a fiber optic stripping tower, and more particularly, to a fiber optic stripping tower coolant, capable of rapidly cooling the molten optical fiber within a melting and demolding furnace. then to a predetermined diameter before the coating is applied.

BACKGROUND OF THE INVENTION In general, optical fibers are obtained by unmolding a preform for the optical fibers, using a fiber optic demoulding tower. Fig. 1 is a schematic view of a general fiber optic demolition tower. The fiber optic stripping tower comprises a casting furnace 12 for melting a preform 10 at a high temperature to unmold the uncoated optical fiber 14, a diameter measurement unit 16 installed below the casting furnace 12, for continuously measuring the outer diameter of the uncoated optical fiber for uniformly controlling the outer diameter of the uncoated optical fiber, a cooling unit 18 below the diameter measuring unit 16, para-cooling REF .: 120635 the temperature of the uncoated optical fiber 14, at room temperature, a coating unit 20 below the cooling unit 18, for coating the surface of the uncoated optical fiber with UV-curable resin, such as acrylic resin or silicone resin for protecting the optical fiber 14 without coating the elements of nature, a solidifying unit 22 below the coating unit 20, for solidifying the coated optical fiber 24, a winch 26 below the unit 22 solidifier, for demolding an optical fiber from the preform 10 in a lower direction, and a spool 28 next to the winch 26, for winding the unmoulded optical fiber. A method for preparing (unmolding) an optical fiber coated with the UV-curable resin will be described. The preform 10 is slowly provided within the casting furnace 12 according to the position control mechanism of a position controller of the preform (not shown). Here, the preform 10 is heated within the melting furnace 12 to several thousand degrees centigrade, typically at 2,100 ~ 2,200 ° C. As a result, the uncoated optical fiber 14 is demolded from the preform 10. Here, the demolding force originates from the winch 26 and is applied to the uncoated optical fiber 14. Then, the diameter measurement unit 16 measures the outer diameter of the optical fiber 14 without unmoulded coating, to determine if the diameter is equal to the predetermined diameter, for example, 125 μm, and sends the value of the measured diameter to the controller of diameter (not shown). The diameter controller controls the rotational speed of the winch 26 such that the diameter of the uncoated optical fiber 14 is maintained at 125 μm. Then, the winch 26 rotates to control the demolding force on the uncoated optical fiber 14 in response to the control of the diameter controller, thereby demolding the uncoated optical fiber 14 in a lower direction. Then, in order to protect the uncoated optical fiber 14 at high speed by the cooling unit 18, the coating unit 20 covers the surface of the optical fiber 14 without falling coating, with the UV-curable resin, for example, acrylic resin or silicone resin. Then, the optical fiber 24 coated with the UV-curable resin is solidified by the solidifying unit 22, and is then wound around the spool 26 under the control of the release force of the winch 26. In addition, while the preform increases, The fiber optic demolition tower should be increased. This is because a very fast demoulding is necessary while the preform increases. After the preform melts as it passes through a melting furnace and is then unmolded, the unmoulded optical fiber is subjected to the coating. Here, prior to the coating of the optical fiber, the temperature of the uncoated optical fiber must be decreased to a predetermined temperature. In general, the temperature of the uncoated optical fiber unmoulded directly from the melting furnace is 2,000 ° C or higher. However, in order to ensure a stable coating on the unmoulded optical fiber, the temperature of the uncoated optical fiber must be cooled to at least 40 ° C or lower (usually at room temperature). For this purpose, the temperature of the uncoated optical fiber is rapidly cooled using a refrigerant. However, the refrigerant in use is not sufficient to cool the uncoated optical fiber to keep pace with the rapid rate of demoulding. Fig. 2 shows a general coolant adopted by the fiber optic stripping tower shown in fig. 1. Inside the refrigerant having a tubular shape, the unmoulded optical fiber is cooled by filling the tube with helium (He). Thus, it is necessary to increase the height of the fiber optic stripping tower in order to rapidly cool the uncoated optical fiber in response to the rapid demoulding speed of the optical fiber. However, making the highest fiber optic demolition tower increases the cost of manufacturing and is not efficient.

DESCRIPTION OF THE INVENTION In order to solve these problems, it is an object of the present invention to provide a coolant for a fiber optic demoulding tower, capable of rapidly cooling an optical fiber that melts into a melting furnace and is then demolded, without increasing the height of a conventional optical fiber stripping tower, such that the optical fiber can be quickly demoulded from a preform. In accordance with one aspect of the present invention, a coolant from an optical fiber stripping tower, located below a foundry furnace to melt a preform for an optical fiber, is provided to cool the unmoulded optical fiber from the molten preform. inside the melting furnace, in which the refrigerant comprises at least one heat exchanger, installed with a predetermined length, surrounding the demoulded optical fiber from the melting furnace, to cool the demoulded optical fiber.

Preferably, the heat exchanger is composed of a thermoelectric cooler (TEC) for taking electric power through a heat absorbing surface to emit heat to the other heat emitting surface and has a tubular shape in which the heat absorbing surface The TEC surrounds the demoulded optical fiber from the melting furnace along the demolding direction by a predetermined length, and the demolded optical fiber is cooled while it passes through the tubular TEC. Preferably, the refrigerant additionally comprises an additional refrigerant bonded to the heat-emitting surface of the TEC, to cool the emitted heat, and the auxiliary refrigerant is installed so as to contact the heat exchanger and comprises a tank in which it is arranged a path of the heat exchange flow medium, a supply tube attached to the tank to supply a heat exchange medium through the path of the heat exchange medium that is flowing, and an exhaust pipe to leak the medium of heat exchange. In accordance with another aspect of the objective, a coolant is provided in an optical fiber stripping tower, located below a casting furnace to melt a preform for an optical fiber, to cool the unmoulded optical fiber from the molten preform within a melting furnace, wherein the coolant has a shape having two openings through which the demolded optical fiber passes in the vertical direction, and comprises two thermoelectric coolers (TECs) each of which has a heat absorbing surface for take electrical energy and another heat emitting surface to emit the heat, arranged such that two heat absorbing surfaces face one another, surrounding the unmoulded optical fiber, and two spacers interposed between the TECs to surround the unmoulded optical fiber. Preferably, the refrigerant further comprises an auxiliary refrigerant bonded to each heat emitting surface of the facing TECs. In addition, at least two coolants can be arranged in the direction of demolding the optical fiber. Preferably, each refrigerant additionally comprises an auxiliary refrigerant bonded to each heat emitting surface of the facing TECs, and an insulating material is interposed between the refrigerants.

Brief description of the illustrations Fig. 1 is a schematic view of a general optical fiber stripping tower; fig. 2 shows a general coolant adopted within the fiber optic stripping tower shown in fig. 1; fig. 3 shows a coolant of an optical power release tower, according to the preferred embodiment of the present invention, which adopts a thermoelectric cooler (TEC) and doubles the cooling effect; fig. 4 is a top view of the refrigerant shown in fig. 3; fig. 5 shows the structure of an example of TEC; fig. 6 shows the positions a, b and c in which the temperatures are measured to illustrate the cooling effect, according to the distance from the preform; fig. 7 is a graph showing the temperature of the optical fiber in position b of FIG. 6, according to the demolding speed, fig. 8 is a graph showing the temperature of the optical fiber at position c of FIG. 6, according to the demolding speed; and fig. 9 is a graph illustrating the change in temperature of an optical fiber, according to the period of time t required for the preform of the position a to be demoulded as an optical fiber, to reach the position c.

The best way to carry out the invention A Peltier effect refers to the change in temperature when the current flows through two different materials that contact one another. A small device in the solid state, such as a heat pump, based on the Peltier effect, is called a "thermoelectric cooler (TEC)". Fig. 5 shows an example of the TEC, in which the pairs of semiconductors type p and type n are arranged in series between two ceramic plates. The basic idea of the present invention is to construct a refrigerant used in a fiber optic demoulding tower, which uses the TEC. Fig. 3 shows a coolant of an optical fiber stripping tower according to the present invention, which adopts the TEC to duplicate the cooling effect. The basic module includes two TECs 300, two bars 310, and an auxiliary refrigerant consisting of three units 320, 330 and 340, which are bonded to each heat emitting surface of the TECs 300. FIG. 4 is a top view of the refrigerant shown in fig. 3. The refrigerant shown in fig. 3 is constituted of two or more basic modules connected to each other, and an insulating material 350, interposed between the basic modules, here, the height of the refrigerant can be controlled by the number of basic modules adopted. The TEC 300 is a heat exchanger to generate heat by taking electrical power through power supply lines 360. The TEC is installed to surround the fiber • optics demoulded from the casting furnace 12 of fig. 1.

That is, the TECs 300 are arranged in such a way that their heat absorbing surfaces face one another around the unmoulded optical fiber from the melting furnace 12. In addition, the fins can be glued to enhance the cooling effect on the heat absorbing surfaces of the TEC 300. In addition, the bars 310 act as a spacer to separate the facing TECs 300 by a predetermined interval. An optical fiber 370 passes through the space enclosed by two TECs 300 and two bars 310 in the vertical direction, and a cooler is supplied to the space to further decrease the temperature of the optical fiber 370. The cooler can be helium (He), Argon (Ar) or nitrogen (N). In this mode, He or Ar is used as the cooler. Here, the three units constitute the auxiliary refrigerant, which adopts a water-cooling system, are a tank 320 in which a path of the heat exchange flow medium is formed, a supply tube 340 attached to the tank 320, for supplying the heat exchange medium through the path of the heat exchange flow medium to the tank 320, and an exhaust pipe 330 for leaking the heat exchange medium. In this mode, water is used as the means of heat exchange. However, any means capable of exchanging heat, for example, oil, can be used in some cases. In addition, the fins can be attached to the tank 320 to enhance its cooling effect. An auxiliary refrigerant that adopts an air cooling system, in which air is supplied using a cooling fan, can be used. That is, the cooling system adopted by the auxiliary refrigerant is not limited to the above-described embodiment according to the present invention. The insulating material 350 blocks the transfer of heat from a higher basic module to a lower basic module, thereby enhancing the cooling efficiency of each basic refrigerant module. The insulating material 350 used in this embodiment is the Styrofoam. However, the insulating material is not limited to the specific material. The refrigerant illustrated in this embodiment has a hexahedral shape, and uncoated optical fiber 370 unmoulded from a casting furnace, is surrounded using two TECs 300 and two bars 310. Preferably, two TECs are used in place of the two bars 310 More preferably, the refrigerant is formed using a tubular TEC. That is, the refrigerant can be modified in several ways without limitations. In addition, the number of basic modules adopted by the refrigerant may be different. That is, in the case where the length of the TEC is sufficient to cool the uncoated optical fiber from the melting furnace while maintaining the passage with the demoulding speed, the coolant can be constituted by only one basic module. Fig. 6 shows the positions a, b and c in which the temperatures are measured to illustrate the cooling effect according to the distance from the preform. The reference character a indicates the bottom line of the preform, the reference characters b and c indicate the separated positions, from the bottom line a, by 100 cm and 200 cm, respectively. Here, the refrigerant is located between positions b and c. In addition, Ts indicates the temperature of the preform, and Ti and T2 indicate the temperatures of the unmoulded optical fiber in positions b and c, respectively. Fig. 7 is a graph showing the temperature T of the unmold optical fiber in position b of FIG. 6, according to the demolding speed Vf. Fig. 8 is a graph showing the temperature x of the unmold optical fiber at position c of FIG. 6, according to the demolding speed Vf. Fig. 9 is a graph illustrating the change in temperature (log (i-T2)) of the optical fiber, according to the time t required for the preform of the position a to be demoulded as an optical fiber to reach the position c. Here, the time t is calculated by L / Vf, where L, the distance between the positions b and c, is 200 cm. In the legend of fig. 9, "He9", MHe6"," He3"and" Hel.5", indicates the cases when the He as cooler flows through the coolant in a flow range of 9, 6, 3 and 1.5 liters per minute, respectively , TEC operates only while the cooler is adopted, "Air" indicates the case where the refrigerant is not operated and cooler is not provided, "He3 ONLY" indicates the case where only He is supplied in a flow range of 3 liters per minute, 'while the refrigerant operation is stopped, and? \ Ar3"indicates the case where Ar is supplied as the cooler in a flow range of 3 liters per minute, while the refrigerant is operated.

INDUSTRIAL APPLICABILITY As described above, the refrigerant for a fiber optic demoulding tower, according to the present invention, can enhance the cooling effect. Thus, the demolding rate of the optical fiber can be increased without increasing the height of the fiber optic demoulding tower. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, the content of the following is claimed as property.

Claims (1)

1. e claims is. A coolant for a fiber optic stripping tower, located below a casting furnace to melt a preform for an optical fiber, for cooling the unmoulded optical fiber from the molten preform within the casting furnace, characterized in that the refrigerant comprises a heat exchanger, at least, installed with a predetermined length surrounding the unmoulded optical fiber from the melting furnace, to cool the unmoulded optical fiber. The refrigerant of claim 1, characterized in that the heat exchanger is formed of a thermoelectric refrigerant (TEC) to take electric power through a heat absorbing surface to emit heat to the other heat emitting surface, and has a tubular shape wherein the heat absorbing surface of the TEC surrounds the unmoulded optical fiber from the melting furnace along the demolding direction by a predetermined length, and the unmoulded optical fiber is cooled while it passes through the tubular TEC. The refrigerant of claim 2, further characterized in that it comprises an auxiliary refrigerant bonded to the heat emitting surface of the TEC, to cool the emitted heat. The refrigerant of claim 3, characterized in that the auxiliary refrigerant is installed by contacting the heat exchanger and comprises a tank in which a flow path of the heat exchange medium is arranged, a supply pipe attached to the tank to supply a means of heat exchange through the path of the heat exchange medium that is flowing, and an exhaust pipe to leak the heat exchange medium. The refrigerant of claim 4, characterized in that the heat exchange medium is water. The refrigerant of claim 2, characterized in that a cooler is flowed into the tubular TEC surrounding the unmoulded optical fiber. The refrigerant of claim 6, characterized in that the cooler is selected from the group consisting of helium (He), argon (Ar) and nitrogen (N). A coolant for a fiber optic stripping tower, located below a casting furnace to melt a preform for an optical fiber, for cooling the unmoulded optical fiber of the molten form inside the casting furnace, characterized in that the coolant has a form having two openings through which the unmoulded optical fiber passes in the vertical direction, and comprises two thermoelectric refrigerants (TECs) each having a heat-absorbing surface for taking electrical energy and the other heat-emitting surface for emitting heat, arranged such two heat absorbing surfaces so as to face each other, surrounding the unmoulded optical fiber, and two spacers interposed between the TECs to surround the unmoulded optical fiber. 9. ' The refrigerant of claim 8, further characterized in that it comprises an auxiliary refrigerant bonded to each heat emitting surface of the facing TECs. The refrigerant of claim 8, characterized in that a cooler is flowed into the space enclosed by the TECs and the spacers. The refrigerant of claim 8, characterized in that two refrigerants, at least, are arranged in the direction of unmoulded optical fiber. The refrigerant of claim 11, characterized in that each refrigerant additionally comprises an auxiliary refrigerant bonded to each heat emitting surface of the TECs they face. The refrigerant of claim 12, characterized in that an insulating material is interposed between the refrigerants.