阅读说明：本技术 一种光纤拉丝冷却系统及其冷却方法 (Optical fiber drawing cooling system and cooling method thereof ) 是由 范修远 张文俊 叶锋 何斐逸 于 2019-11-19 设计创作，主要内容包括：本发明提出一种光纤拉丝冷却系统,其包括冷却管体、冷却油循环装置、气体循环装置,冷却管体包括供光纤通过的内腔和形成于冷却管体管壁内的环形空腔,冷却管体的两侧分别开设多个进气通道和泄气通道,进气通道和泄气通道与内腔相连通,冷却管体的内壁上设置多个引导片,引导片关于冷却管体的中心轴线呈轴向对称分布,在竖直方向上,进气通道、泄气通道位于相邻的两个引导片之间,冷却油循环装置通过冷却油管与环形空腔的上端和下端连接,构成冷却油循环系统,气体循环装置通过气体管道与进气通道和泄气通道连接,构成气体循环系统。该冷却系统提高了光纤的冷却效率,并降低了冷却介质的使用量,降低了光纤拉丝的生产成本。本发明还提出一种光纤拉丝冷却方法。(The invention provides an optical fiber drawing cooling system which comprises a cooling pipe body, a cooling oil circulating device and a gas circulating device, wherein the cooling pipe body comprises an inner cavity for optical fibers to pass through and an annular cavity formed in the pipe wall of the cooling pipe body, a plurality of air inlet channels and air outlet channels are respectively formed in two sides of the cooling pipe body and communicated with the inner cavity, a plurality of guide pieces are arranged on the inner wall of the cooling pipe body, the guide pieces are axially and symmetrically distributed around the central axis of the cooling pipe body, the air inlet channels and the air outlet channels are positioned between two adjacent guide pieces in the vertical direction, the cooling oil circulating device is connected with the upper end and the lower end of the annular cavity through cooling oil pipes to form a cooling oil circulating system, and the gas circulating device is connected with the air inlet channels and the air outlet channels through gas pipelines to form a gas circulating system. The cooling system improves the cooling efficiency of the optical fiber, reduces the usage amount of cooling medium and reduces the production cost of optical fiber drawing. The invention also provides an optical fiber drawing cooling method.)

1. An optical fiber drawing cooling system, comprising: cooling tube body, coolant oil circulating device, gas circulating device, the cooling tube body is including the inner chamber that supplies optic fibre to pass through and the toroidal cavity that is formed in the cooling tube body pipe wall, a plurality of inlet channels and the passageway of disappointing are seted up respectively to the both sides of cooling tube body, inlet channel with lose heart the passageway with the inner chamber is linked together, set up a plurality of guide pieces on the inner wall of cooling tube body, the guide piece is axial symmetry about the central axis of cooling tube body and distributes, in vertical direction, inlet channel, lose heart the passageway are located between two adjacent guide pieces, coolant oil circulating device pass through cooling oil pipe with toroidal cavity's upper end and lower extreme are connected, constitute coolant oil circulating system, gas circulating device pass through gas conduit with inlet channel and the passageway connection that loses heart constitute gas circulating system.

2. The optical fiber drawing cooling system according to claim 1, wherein the air inlet passage and the air outlet passage extend in a direction intersecting with the direction of extension of the inner cavity.

3. The optical fiber drawing cooling system according to claim 2, wherein the guide piece comprises a first metal piece and a second metal piece which are different in size, the first metal piece and the second metal piece are respectively distributed in axial symmetry about a central axis of the cooling pipe body in a horizontal direction, and the first metal piece and the second metal piece are distributed on the inner wall in a staggered manner in a vertical direction.

4. The optical fiber drawing cooling system according to claim 3, wherein the first metal piece and the second metal piece extend from the inner wall of the cooling pipe body toward the central axis of the cooling pipe body and downward in an inclined state.

5. The optical fiber drawing cooling system according to claim 4, wherein the first metal sheet and the second metal sheet are uniformly distributed on the inner wall of the cooling tube body, and the air inlet channels and the air outlet channels correspond to each other in a one-to-one manner in the horizontal direction.

6. The optical fiber drawing cooling system according to claim 4, wherein each of the air inlet channel and the air outlet channel is located between the adjacent first metal sheet and the second metal sheet in a vertical direction.

7. The optical fiber drawing cooling system according to claim 6, wherein the cooling oil circulating device comprises an oil storage tank, an oil cooling machine and a cold oil pump which are connected in sequence, the oil storage tank is communicated with the lower end of the annular cavity, and the cold oil pump is communicated with the upper end of the annular cavity.

8. The optical fiber drawing cooling system according to claim 6, further comprising a gas flow control device connected between the gas inlet channel and the gas circulation device, the gas circulation device comprising a gas buffer tank, a gas purifier, a refrigerator, and a dryer connected in series.

9. An optical fiber drawing cooling method realized by the optical fiber drawing cooling system according to claim 1, comprising:

(1) opening a gas circulating device and a cooling oil circulating device, wherein the gas circulating device is used for refrigerating gas and sending the refrigerated cooling gas into an inner cavity of a cooling pipe body from a gas inlet channel, the cooling oil circulating device is used for cooling oil and sending the cooled super-cooling oil into an annular cavity of the cooling pipe body, and meanwhile, optical fibers come out of a wire drawing furnace mouth and enter the inner cavity of the cooling pipe body;

(2) under the flow guiding action of the guide sheet in the inner cavity, the cooling gas forms a circular flow in the inner cavity, the optical fiber takes away part of the cooling gas in the circular flow along with downward drawing of the optical fiber, the part of the cooling gas is subjected to heat exchange with the optical fiber, and heat is transferred from the optical fiber to the part of the cooling gas to form hot gas;

(3) the mass of the cooling gas is lighter than that of air, the temperature in the inner cavity is increased, the hot gas moves upwards, in the upward movement process, part of the hot gas exchanges heat with the circulating cooling gas to transfer heat to the circulating cooling gas, and the other part of the hot gas enters the gas circulating device from the gas release channel;

(4) after absorbing heat, the circulating cooling gas is continuously contacted with the inner wall of the cooling pipe body to exchange heat with the inner wall, so that the heat is transferred to the inner wall, and the low-temperature stability of the circulating gas is ensured;

(5) the inner wall of the cooling pipe body exchanges heat with the super-cooled oil in the annular cavity, heat is transferred to the super-cooled oil, and the super-cooled oil absorbs the heat and then enters the cooling oil circulating device through the cooling oil pipe to be cooled again for recycling.

10. The optical fiber drawing cooling method according to claim 9, wherein the cooling gas is helium, the cooling oil is silicone oil, and the silicone oil is cooled in a cooling oil circulating device to super-cooling oil having a temperature of-100 ℃ to-200 ℃.

Technical Field

The invention relates to the field of optical fiber manufacturing, in particular to an optical fiber drawing cooling system and a cooling method thereof.

Background

The manufacture of communication optical fiber is divided into two procedures of rod making and wire drawing. Wherein, the optical fiber drawing is a process of melting the preform at a high temperature by a drawing machine to draw an optical fiber having an outer diameter of 125 μm. Specifically, the preform is placed in a heating furnace at the top end of a drawing machine, when the temperature of the furnace rises to about 2200 ℃, the viscosity of the tip of the preform becomes low, the preform gradually sags by self weight and becomes a bare fiber, and the bare fiber passes through a laser diameter measuring monitor and then enters a coating curing system.

When optical fiber is drawn at a high speed, the temperature of the optical fiber coming out of the drawing furnace is high, generally between 1600 ℃ and 2000 ℃, if the optical fiber coming out of the drawing furnace directly enters the coating system, the coating of the optical fiber is abnormal, and the transmission performance of the optical fiber is further influenced, so that in order to reduce the temperature of the surface of the optical fiber before entering the coating system and improve the coating efficiency of the optical fiber, a cooling device is often added between the drawing furnace and the coating system to force the optical fiber to be cooled quickly.

At present, the commonly used optical fiber cooling device mainly comprises a cooling pipe body, a cooling water pipe and a cooling water circulating device, wherein inert gases such as helium, argon and the like are introduced into the cooling pipe body. Although the device can reduce the temperature of the optical fiber before entering the coating system, the temperature of the cooling water pipe can only be maintained between 0 ℃ and 20 ℃, so that the inert gas flow needs to be increased to realize a good refrigeration effect, which undoubtedly increases the production cost of optical fiber drawing.

Chinese patent application publication No. CN108002697A proposes an on-line cooling spray type cooling device, in which gas is cooled by using cryogenic liquid instead of normal temperature water, wherein the cryogenic liquid mainly includes liquid nitrogen, liquid oxygen, liquid carbon dioxide, liquefied air, and the like. Although this patent application can maintain the ambient temperature of the cooling tube within a low range, the low thermal conductivity of the cryogenic liquid reduces the cooling efficiency of the optical fiber to some extent.

Chinese patent No. CN104496170B proposes an optical fiber drawing cooling device using H2, where H2 has a thermal conductivity higher than that of inert gas, so that the device has a good cooling effect, but in order to prevent safety accidents caused by H2 leakage, the device needs to have complete equipment, and needs to redesign the plant, which increases the production cost of optical fibers.

Disclosure of Invention

In order to solve the problems in the prior art, the invention aims to provide an optical fiber drawing cooling system and a cooling method thereof, which optimize the existing optical fiber drawing cooling device and method, improve the cooling efficiency of optical fibers, reduce the usage amount of cooling media and greatly reduce the production cost of optical fiber drawing.

In order to achieve the purpose, the optical fiber drawing cooling system comprises a cooling pipe body, a cooling oil circulating device and a gas circulating device, wherein the cooling pipe body comprises an inner cavity for optical fibers to pass through and an annular cavity formed in the pipe wall of the cooling pipe body, a plurality of air inlet channels and air outlet channels are respectively formed in two sides of the cooling pipe body and communicated with the inner cavity, a plurality of guide pieces are arranged on the inner wall of the cooling pipe body, the guide pieces are axially and symmetrically distributed around the central axis of the cooling pipe body, the air inlet channels and the air outlet channels are located between two adjacent guide pieces in the vertical direction, the cooling oil circulating device is connected with the upper end and the lower end of the annular cavity through cooling oil pipes to form a cooling oil circulating system, and the gas circulating device is connected with the air inlet channels and the air outlet channels through gas pipelines to form a gas circulating system.

Further, the extending direction of the air inlet channel and the air outlet channel is crossed with the extending direction of the inner cavity.

Further, the guide sheet comprises a first metal sheet and a second metal sheet, the first metal sheet and the second metal sheet are different in size, the first metal sheet and the second metal sheet are respectively distributed in an axially symmetrical mode about the central axis of the cooling pipe body in the horizontal direction, and the first metal sheet and the second metal sheet are distributed on the inner wall in a staggered mode in the vertical direction.

Further, the first metal sheet and the second metal sheet extend downwards from the inner wall of the cooling pipe body to the center of the inner cavity and are in an inclined state.

Furthermore, first sheetmetal and second sheetmetal distribute evenly on the cooling tube inner wall, in the horizontal direction, inlet channel and the passageway one-to-one that loses heart.

Further, each of the air intake passage and the air discharge passage is located between the adjacent first metal sheet and the second metal sheet in the vertical direction.

Further, the cooling oil circulating device comprises an oil storage tank, an oil cooler and a cold oil pump which are sequentially connected, wherein the oil storage tank is communicated with the lower end of the annular cavity, and the cold oil pump is communicated with the upper end of the annular cavity.

Further, still include gas flow control device, gas flow control device connects between inlet channel and gas circulation device, and gas circulation device is including the gas surge tank, gaseous clearing machine, refrigerator, the desiccator that connect gradually.

The invention also provides an optical fiber drawing cooling method, which comprises the following steps:

(1) opening a gas circulating device and a cooling oil circulating device, wherein the gas circulating device is used for refrigerating gas and sending the refrigerated cooling gas into an inner cavity of a cooling pipe body from a gas inlet channel, the cooling oil circulating device is used for cooling oil and sending the cooled super-cooling oil into an annular cavity of the cooling pipe body, and meanwhile, optical fibers come out of a wire drawing furnace mouth and enter the inner cavity of the cooling pipe body;

(2) under the flow guiding action of the first metal sheet and the second metal sheet in the inner cavity, the cooling gas forms a circular flow in the inner cavity, as the optical fiber is drawn downwards, the optical fiber takes away part of the cooling gas in the circular flow, the part of the cooling gas is subjected to heat exchange with the optical fiber, and heat is transferred from the optical fiber to the part of the cooling gas to form hot gas;

(3) the mass of the cooling gas is lighter than that of air, the temperature in the inner cavity is increased, the hot gas moves upwards, in the upward movement process, part of the hot gas exchanges heat with the circulating cooling gas to transfer heat to the circulating cooling gas, and the other part of the hot gas enters the gas circulating device from the gas release channel;

(4) after absorbing heat, the circulating cooling gas is continuously contacted with the inner wall of the cooling pipe body to exchange heat with the inner wall, so that the heat is transferred to the inner wall, and the low-temperature stability of the circulating gas is ensured;

(5) the inner wall of the cooling pipe body exchanges heat with the super-cooled oil in the annular cavity, heat is transferred to the super-cooled oil, and the super-cooled oil absorbs the heat and then enters the cooling oil circulating device through the cooling oil pipe to be cooled again for recycling.

Furthermore, the cooling gas is helium, the cooling oil is silicon oil, and the silicon oil is cooled to super-cooling oil with the temperature of-100 ℃ to-200 ℃ in a cooling oil circulating device.

The optical fiber drawing cooling system and the cooling method thereof have the following beneficial effects:

(1) the optical fiber drawing cooling system provided by the invention adopts a novel cooling pipe body, the cooling pipe body is internally provided with the guide piece, and the arrangement of the air inlet channel and the air outlet channel is combined, so that cooling gas entering an inner cavity forms circulation, the circulation gas is continuously contacted with the inner wall of the cold pipe body in the flowing process, the heat exchange area is indirectly increased, the cooling efficiency is improved, in addition, the circulation gas movement mode improves the utilization rate of the cooling gas, reduces the gas usage amount and saves the cost;

(2) the invention adopts two modes of gas cooling and oil cooling, the cooling gas directly cools the optical fiber, the cooling oil cools the cooling pipe body, and can reduce the temperature of the cooling gas absorbing heat and indirectly cool the optical fiber, and the two cooling modes interact with each other to jointly cool, thereby greatly improving the cooling effect.

(3) The oil cooling mode is adopted to replace the traditional water cooling mode, the refrigeration temperature is lower, the cooling pipe body can be maintained within the range of-100 ℃ to-200 ℃, the heat exchange rate of the cooling oil is high, the cooling effect of the optical fiber can be greatly improved, and therefore the purposes of shortening the cooling distance and improving the wire drawing rate can be achieved;

(4) because the cooling gas is light, the cooling gas rises to the top of the cooling tube body after absorbing heat, the hot gas can be quickly discharged through the air leakage channel above the side wall of the cooling tube body, and the hot gas is conveyed to the gas circulation device and then conveyed to the inner cavity of the cooling tube body again after being refrigerated, so that the cyclic utilization of the cooling gas is realized, and the production cost is saved.

Drawings

The present invention will be further described and illustrated with reference to the following drawings.

FIG. 1 is a schematic diagram of an optical fiber draw cooling system in accordance with a preferred embodiment of the present invention.

Detailed Description

The technical solution of the present invention will be more clearly and completely explained by the description of the preferred embodiments of the present invention with reference to the accompanying drawings.

As shown in fig. 1, an optical fiber drawing cooling system according to a preferred embodiment of the present invention includes a cooling pipe body 1, a cooling oil circulation device 2, and a gas circulation device 3, wherein the cooling oil circulation device 2 and the gas circulation device 3 are connected to the cooling pipe body 1 for reducing the temperature of an optical fiber.

The cooling tube body 1 comprises an inner cavity 11 for passing the optical fiber and an annular cavity 12 formed in the wall of the cooling tube body, wherein the annular cavity 12 surrounds the inner cavity 11. The optical fiber 10 comes out of the drawing furnace mouth and enters the inner cavity 11 of the cooling tube body.

A plurality of air inlet channels 13 and air outlet channels 14 are respectively arranged on two sides of the cooling pipe body 1 and are communicated with the inner cavity 11. The air inlet channel 13 enables cooling gas to enter the inner cavity 11 to cool the optical fiber; the air escape channels 14 allow the cooling gas to flow out of the inner cavity 11 after absorbing heat. The extending direction of the air intake passage 13 and the air discharge passage 14 intersects the extending direction of the inner cavity 11. Preferably, the extending direction of the air inlet channel 13 and the air outlet channel 14 is perpendicular to the extending direction of the inner cavity 11, and the air inlet channel 13 and the air outlet channel 14 are distributed on two sides of the cooling pipe body 1 at equal intervals and are in one-to-one correspondence, that is, the air inlet channel 13 and the air outlet channel 14 are aligned in the horizontal direction, which is beneficial to the gas discharge.

The inner wall of the cooling tube body 1 is provided with a plurality of guide pieces 4 for guiding the airflow to flow, and the guide pieces 4 are axially and symmetrically distributed about the central axis X of the cooling tube body 1. Specifically, the guide piece 4 includes a first metal piece 41 and a second metal piece 42, which are different in size. In the present embodiment, the first metal sheet 41 is larger in size than the second metal sheet 42, specifically, the first metal sheet 41 is longer than the second metal sheet 42. In the horizontal direction, the first metal sheets 41 and the second metal sheets 42 are respectively axially symmetrical with respect to the central axis X, i.e., in the same horizontal direction, the two first metal sheets 41 are aligned, and the two second metal sheets 42 are aligned; in the vertical direction, the first metal sheets 41 and the second metal sheets 42 are staggered, i.e. the first metal sheets 41 and the second metal sheets 42 are adjacent. Preferably, the first metal sheets 41 and the second metal sheets 42 are equally spaced on the inner wall. In the vertical direction, the air intake passage 13 and the air discharge passage 14 are located between two adjacent guide pieces 4, that is, between the adjacent first metal piece 41 and second metal piece 42.

The invention adopts the design of metal sheets with alternate lengths, effectively reduces the movement rate of the exchanged gas, prolongs the retention time of the gas in the cooling pipe, enhances the cooling effect on one hand, and reduces the gas consumption cost on the other hand. Sheet metal designs of different sizes have significant advantages in terms of cooling effectiveness and cost compared to sheet metal of the same size.

The first metal sheet 41 and the second metal sheet 42 extend downward from the inner wall of the cooling pipe toward the central axis X of the inner cavity in an inclined state at an inclination angle α of 30 ° to 70 °.

In this embodiment, preferably, the inner diameter of the cooling tube 1 is 15-30 mm, and the length of the guide pieces 4 is 3-6 mm and the total number of the guide pieces 4 is 10-30 in a size matching with the cooling tube, so that the cooling tube has a good cooling effect without affecting the drawing of the optical fiber. In other embodiments, the size and number of the guide tabs may be determined according to the size of the cooling pipe body.

The cooling oil circulating device 2 comprises an oil storage tank 21, an oil cooler 22 and a cold oil pump 23 which are sequentially connected, wherein the oil storage tank 21 is connected with the lower end of the annular cavity 12 through a cold oil pipe 24, and the cold oil pump 23 is connected with the upper end of the annular cavity 12 through the cold oil pipe 24. Thus, the cooling oil circulating device 2 and the annular cavity 12 constitute a cooling oil circulating system. The oil cooler 22 is used for cooling the cooling oil to obtain super-cooled oil at the temperature of-100 ℃ to-200 ℃. The cold oil pump 23 pumps ultra-cold oil into the annular cavity 12, and heat exchange is performed between the inner wall of the cooling pipe body 1 and the high temperature in the inner cavity 11, so that the temperature of the inner cavity is reduced. The cooling oil in the annular cavity 12 returns to the oil storage tank 21 after absorbing heat, forms super-cooling oil after being cooled by the oil cooler 22, and is pumped into the annular cavity 12 again, so that the circulating cooling of the inner cavity 11 and the optical fiber 10 is realized. Preferably, the cooling oil is silicon oil which is a heat conduction medium with higher heat conductivity coefficient, the heat exchange rate is high, and the cooling effect of the optical fiber can be greatly improved.

The gas circulation device 3 comprises a gas buffer tank 31, a gas purifier 32, a refrigerator 33 and a dryer 34 which are connected in sequence, wherein the dryer 34 is connected with the gas inlet channel 13 through a gas pipeline, and the gas buffer tank 31 is connected with the gas release channel 14 through a gas pipeline. Thus, the gas circulation device 3 and the inner chamber 11 constitute a gas circulation system. The gas purifier 32, the refrigerator 33, and the dryer 34 purify, cool, and dry the gas, respectively. Preferably, the cooling gas is helium, because helium has light weight, and after absorbing heat, the helium rises to the top of the inner cavity and is discharged from the air leakage channel above the side wall of the cooling tube body.

The gas circulation system further comprises a gas flow control device connected between the gas circulation device 3 and the gas inlet channel 13 for adjusting the gas flow and maintaining the stability of the gas in the inner cavity of the cooling tube body. Preferably, the air inlet flow speed is controlled to be between 3 and 8L/min.

The upper end opening and the lower end opening of the cooling pipe body 1 are provided with gas sealing devices 5 containing variable grating blades, and the gas sealing devices are used for adjusting and reducing the leakage amount of cooling gas in the inner cavity 11.

The method for cooling the optical fiber drawn wire by using the optical fiber drawn wire cooling device comprises the following steps:

(1) firstly, opening a cooling oil circulating device 2 and a gas circulating device 3, refrigerating gas by the gas circulating device 3, sending the refrigerated cooling gas into an inner cavity 11 of a cooling pipe body from a gas inlet channel 13, cooling oil by the cooling oil circulating device 2 to form super-cooling oil, sending the super-cooling oil into an annular cavity 12 of the cooling pipe body 1, and simultaneously enabling optical fibers 10 to come out of a drawing furnace mouth and enter the inner cavity 11 of the cooling pipe body;

(2) under the guide action of the guide sheet 4, the cooling gas forms a circular flow in the inner cavity 11, as the optical fiber is drawn downwards, the optical fiber takes away part of the cooling gas in the circular flow, the part of the cooling gas exchanges heat with the optical fiber, and heat is transferred from the optical fiber to the part of the cooling gas to form hot gas;

(3) the mass of the cooling gas is lighter than that of air, the temperature in the inner cavity is increased, the hot gas moves upwards, as shown by the arrows in fig. 1, during the upward movement, a part of the hot gas exchanges heat with the circulating cooling gas to transfer heat to the circulating cooling gas, and the other part of the hot gas enters the gas circulating device 3 from the gas release passage 14;

(4) after absorbing heat, the circulating cooling gas is continuously contacted with the inner wall of the cooling pipe body to exchange heat with the inner wall, so that the heat is transferred to the inner wall, and the low-temperature stability of the circulating gas is ensured;

(5) the inner wall of the cooling pipe body exchanges heat with the super-cooled oil in the annular cavity 12, heat is transferred to the super-cooled oil, and the super-cooled oil absorbs the heat and then enters the cooling oil circulating device 2 through the cooling oil pipe 24 to be cooled again and then recycled.

The above detailed description merely describes preferred embodiments of the present invention and does not limit the scope of the invention. Without departing from the spirit and scope of the present invention, it should be understood that various changes, substitutions and alterations can be made herein by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. The scope of the invention is defined by the claims.