阅读说明：本技术 一种低氦气用量的光纤拉丝炉 (Optical fiber drawing furnace with low helium consumption ) 是由 刘旋 吕净宇 李惠辉 于 2021-01-14 设计创作，主要内容包括：本申请涉及一种低氦气用量的光纤拉丝炉,涉及光纤制造技术领域,其包括拉丝炉本体和第一进气口,拉丝炉本体内沿长度方向设有相互连通的光纤预制棒加热区和光纤成型区；拉丝炉本体的两端分别开设有两个排气口,两个排气口分别与光纤预制棒加热区和光纤成型区相连通；第一进气口位于两个排气口之间,且第一进气口与光纤成型区相连通,以供第一气体通入光纤成型区内,并从两个排气口排出。本申请通过采用从第一进气口通气,并分别往上下排气的方式,大大降低了第一气体排出炉体的速率,提高了第一气体在炉体内停留的时间,在对光纤成型的过程起到保护作用的同时,大大降低了第一气体中氦气的用量。(The application relates to an optical fiber drawing furnace with low helium consumption, which relates to the technical field of optical fiber manufacturing and comprises a drawing furnace body and a first air inlet, wherein an optical fiber perform heating area and an optical fiber forming area which are communicated with each other are arranged in the drawing furnace body along the length direction; two ends of the wire drawing furnace body are respectively provided with two exhaust ports which are respectively communicated with the optical fiber preform heating area and the optical fiber forming area; the first air inlet is positioned between the two air outlets and communicated with the optical fiber forming area so as to allow first air to enter the optical fiber forming area and be discharged from the two air outlets. This application is ventilated from first air inlet through the adoption to past carminative mode from top to bottom respectively, greatly reduced the speed of first gas discharge furnace body, improved the time of first gas at the internal dwell of furnace, when playing the guard action to the fashioned process of optic fibre, greatly reduced the quantity of helium in the first gas.)

1. An optical fiber drawing furnace with low helium usage, characterized in that it comprises:

the drawing furnace comprises a drawing furnace body (1), wherein an optical fiber preform heating area (10) and an optical fiber forming area (11) which are communicated with each other are arranged in the drawing furnace body along the length direction; two exhaust ports (12) are respectively formed in two ends of the wire drawing furnace body (1), and the two exhaust ports (12) are respectively communicated with the optical fiber preform heating area (10) and the optical fiber forming area (11);

the first air inlet (2) is positioned between the two air outlets (12), and the first air inlet (2) is communicated with the optical fiber forming area (11) so as to allow first air to enter the optical fiber forming area (11) and be discharged from the two air outlets (12).

2. The low helium usage optical fiber draw furnace of claim 1, wherein the first gas comprises a mixture of helium and argon, and wherein a flow rate of the helium gas is greater than a flow rate of the argon gas.

3. The low helium usage optical fiber draw furnace of claim 2, wherein the flow rate of helium is twice the flow rate of argon.

4. The low helium usage optical fiber draw furnace of claim 1, further comprising:

a separation hood (3), the separation hood (3) being located in the optical fiber molding zone (11) and separating the optical fiber molding zone (11) into a first air flow channel (110) located outside the separation hood (3) and a second air flow channel (111) located inside the separation hood (3); the second air flow channel (111) is communicated with the first air inlet (2);

the second gas inlet (4) is communicated with the first gas flow channel (110) so that second gas can be introduced into the first gas flow channel (110) and discharged from a gas outlet (12) positioned at the upper end of the wire drawing furnace body (1).

5. The low helium usage optical fiber draw furnace of claim 4, wherein the second gas is argon.

6. The low helium usage optical fiber draw furnace of claim 4, wherein the second gas has a gas flow rate equal to the first gas.

7. The low helium usage optical fiber drawing furnace according to claim 1, further comprising a vacuum pump communicating with an exhaust port (12) at an upper end of the drawing furnace body (1) and adapted to draw air from the exhaust port (12).

8. The low helium usage optical fiber draw furnace of claim 1, further comprising a flow guiding structure (5), wherein the flow guiding structure (5) is located at a boundary between the optical fiber preform heating zone (10) and the inner fiber shaping zone (11), and the flow guiding structure (5) is configured to guide the first gas in the optical fiber shaping zone (11) into the optical fiber preform heating zone (10).

9. The low helium usage optical fiber drawing furnace according to claim 8, wherein the inner wall of the guiding structure (5) is a guiding surface (50) inclined downwards.

10. The low helium usage optical fiber drawing furnace according to claim 1, further comprising an extension tube (6), wherein said extension tube (6) is disposed at a bottom end of said drawing furnace body (1) and is in communication with said optical fiber forming region (11); and an exhaust port (12) positioned at the bottom end of the wire drawing furnace body (1) is arranged on the extension pipe (6).

Technical Field

The application relates to the technical field of optical fiber manufacturing, in particular to an optical fiber drawing furnace with low helium consumption.

Background

At present, in the optical fiber production process, helium is used as a protective gas, so that heat can be rapidly led out in the drawing process, and the optical fiber can be protected in the range of inert gas. The method for protecting the gas can effectively increase the drawing speed of the optical fiber and the quality of the optical fiber.

Helium is widely applied to the field of industrial production due to the advantages of stability, small molecular weight, good heat conductivity and the like, and is used as a non-renewable resource, the demand is continuously increased along with the lapse of time, the stock is continuously reduced, and the situation of sudden price rise and short supply and demand is caused.

In the related art, fiber manufacturers and research institutions intend to adopt other substitute gases as shielding gases through gas research. However, practical results show that other kinds of drawing protection gases cannot completely meet the requirements due to the aspects of heat conductivity, inertia and the like. After the inert gas is replaced, it can only be compensated by sacrificing the drawing speed and the quality of the optical fiber.

In addition, the usage amount of helium is reduced by optimizing the process and the equipment, or the helium is recycled by a recycling device. The helium cost of wire drawing is reduced by the method.

However, referring to fig. 1, the air flow pattern inside the conventional optical fiber drawing furnace is a lower exhausting manner, which has a serious influence on the quality of the optical fiber by excessively reducing the amount of helium used when the demand for helium is high.

Disclosure of Invention

The embodiment of the application provides an optical fiber wire drawing stove of low helium quantity to the optical fiber wire drawing stove in solving the correlation technique adopts down carminative mode, and is very big to the demand volume of helium, reduces the helium quantity in trade, then can cause the problem of serious influence to the quality of optic fibre.

In a first aspect, there is provided a low helium usage optical fiber draw furnace comprising:

the optical fiber drawing furnace comprises a drawing furnace body, wherein an optical fiber preform heating area and an optical fiber forming area which are communicated with each other are arranged in the drawing furnace body along the length direction; two ends of the wire drawing furnace body are respectively provided with two exhaust ports, and the two exhaust ports are respectively communicated with the optical fiber preform heating area and the optical fiber forming area;

the first air inlet is positioned between the two air outlets and communicated with the optical fiber forming area so that first air can be introduced into the optical fiber forming area and discharged from the two air outlets.

In some embodiments, the first gas comprises a mixture of helium and argon, and a gas flow rate of the helium is greater than a gas flow rate of the argon.

In some embodiments, the flow rate of helium is twice the flow rate of argon.

In some embodiments, the optical fiber drawing furnace further comprises:

a separating hood located within the fiber forming region and separating the fiber forming region into a first airflow channel located outside the separating hood and a second airflow channel located inside the separating hood; the second air flow channel is communicated with the first air inlet;

and the second gas inlet is communicated with the first gas flow channel so that second gas is introduced into the first gas flow channel and is discharged from a gas outlet at the upper end of the wire drawing furnace body.

In some embodiments, the second gas is argon.

In some embodiments, the second gas has a gas flow rate equal to the first gas.

In some embodiments, the optical fiber drawing furnace further comprises a vacuum pump in communication with an exhaust port located at an upper end of the furnace body and adapted to draw air from the exhaust port.

In some embodiments, the optical fiber drawing furnace further comprises a flow guide structure located at a boundary between the optical fiber preform heating zone and the inner optical fiber forming zone, and the flow guide structure is configured to guide the first gas in the optical fiber forming zone into the optical fiber preform heating zone.

In some embodiments, the inner wall of the flow guiding structure is a guide surface inclined downwards.

In some embodiments, the optical fiber drawing furnace further comprises an extension tube, wherein the extension tube is arranged at the bottom end of the drawing furnace body and is communicated with the optical fiber forming area; and the exhaust port positioned at the bottom end of the wire drawing furnace body is arranged on the extension pipe.

The beneficial effect that technical scheme that this application provided brought includes: the utility model provides an optic fibre wire drawing stove of low helium quantity is through adopting from first air inlet to past carminative mode from top to bottom respectively, greatly reduced the speed of first gas discharge furnace body, improved the time of first gas dwell in the furnace body, when playing the guard action to the fashioned process of optic fibre, greatly reduced the quantity of helium in the first gas. And the first gas enters the optical fiber forming area from the first gas inlet, the first gas is naturally divided into two gas flows once entering the optical fiber forming area, the gas flow flowing downwards is not generated by the backflow of the gas flow flowing upwards, the turbulence phenomenon caused by the backflow of the gas is avoided, the gas flow flowing downwards forms stable laminar flow on the surface of the optical fiber, the diameter stability of the optical fiber is ensured, and the quality of the optical fiber is improved.

The embodiment of the application provides an optical fiber drawing furnace with low helium consumption, because first gas is introduced from a first gas inlet, the first gas is divided into two streams of gas flow when entering an optical fiber forming area from the first gas inlet, one stream of gas flow flows upwards along the optical fiber forming area and is discharged from a gas outlet positioned at the upper end of a drawing furnace body, and the upwards flowing gas flow forms a laminar flow tightly attached to the surface of an optical fiber preform in an optical fiber preform heating area and is used for protecting the optical fiber preform in the optical fiber preform heating area; the other air flow flows downwards along the optical fiber forming area under the traction action of the optical fiber and is discharged from the exhaust port at the lower end of the drawing furnace body, and the air flow flowing downwards is used for cooling the optical fiber in the optical fiber forming area, so that the air flow flowing downwards is not generated by the backflow of the air flow flowing upwards, the turbulence phenomenon caused by the backflow of the air is avoided, the air flow flowing downwards forms stable laminar flow on the surface of the optical fiber, the diameter stability of the optical fiber is ensured, and the quality of the optical fiber is improved; and greatly reduced the speed that first gas discharged the furnace body, improved the time that first gas stayed in the furnace body, when playing the guard action to the fashioned process of optical fiber, greatly reduced the quantity of helium in the first gas.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic view of a bottom vented optical fiber drawing furnace according to the prior art;

FIG. 2 is a schematic diagram of a low helium usage fiber draw furnace according to an embodiment of the present disclosure;

FIG. 3 is a schematic view of the flow of gas in a drawing furnace in the example of the present application.

In the figure: 1. a wire drawing furnace body; 10. an optical fiber preform heating zone; 11. an optical fiber molding region; 110. a first air flow passage; 111. a second airflow channel; 12. an exhaust port; 2. a first air inlet; 3. a separation cover; 4. a second air inlet; 5. a flow guide structure; 50. a guide surface; 6. and (4) extending the tube.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Referring to fig. 2, the embodiment of the present application provides an optical fiber drawing furnace with low helium usage, which includes a drawing furnace body 1 and a first air inlet 2, wherein an optical fiber preform heating area 10 and an optical fiber forming area 11, which are communicated with each other, are arranged in the drawing furnace body 1 along a length direction; the optical fiber preform heating zone 10 is mainly used for accommodating the optical fiber preform and heating the optical fiber preform, and the optical fiber forming zone 11 is used for accommodating the optical fiber after wiredrawing forming; two exhaust ports 12 are respectively formed at two ends of the wire drawing furnace body 1, and the two exhaust ports 12 are respectively communicated with the optical fiber preform heating area 10 and the optical fiber forming area 11; the first gas inlet 2 is located between the two gas outlets 12, and the first gas inlet 2 is communicated with the optical fiber forming region 11, so that the first gas is introduced into the optical fiber forming region 11 and discharged from the two gas outlets 12. Wherein the first gas comprises helium.

The working principle of the optical fiber drawing furnace with low helium consumption in the embodiment of the application is as follows:

referring to fig. 3, solid arrows indicate the flow direction of the first gas. Introducing first gas from a first gas inlet 2, dividing the first gas into two gas flows when the first gas enters an optical fiber forming area 11 from the first gas inlet 2, wherein one gas flow flows upwards along the optical fiber forming area 11 and is discharged from a gas outlet 12 positioned at the upper end of a wire drawing furnace body 1, and the upwards flowing gas flows form laminar flow clinging to the surface of an optical fiber preform in an optical fiber preform heating area 10 and are used for protecting the optical fiber preform in the optical fiber preform heating area 10; the other air current flows downwards along the optical fiber forming area 11 under the traction action of the optical fiber and is discharged from an exhaust port 12 positioned at the lower end of the drawing furnace body 1, and the air current flowing downwards is used for cooling the optical fiber in the optical fiber forming area 11.

The optical fiber wire drawing stove of low helium quantity of this application embodiment is through adopting from first air inlet 2 to ventilate to up respectively and down carminative mode, greatly reduced the speed of first gas discharge furnace body, improved the time of first gas dwell in the furnace body, when playing the guard action to optical fiber shaping process, greatly reduced the quantity of helium in the first gas. And the first gas enters the optical fiber forming area 11 from the first gas inlet 2, the first gas is naturally divided into two gas flows once entering the optical fiber forming area 11, the downward flowing gas flow is not generated by the backflow of the upward flowing gas flow, the turbulent flow phenomenon caused by the backflow of the gas is avoided, the downward flowing gas flow forms stable laminar flow on the surface of the optical fiber, the diameter stability of the optical fiber is ensured, and the quality of the optical fiber is improved.

Optionally, the first gas includes a mixed gas composed of helium and argon, and a gas flow rate of the helium is greater than a gas flow rate of the argon.

Because the upward flowing speed of the first gas introduced from the first gas inlet 2 is greatly lower than the flowing speed of the existing lower exhaust mode, the flowing time of the first gas in the furnace body is prolonged, the protection time is prolonged, the helium consumption can be saved, and the molding of the optical fiber can not be influenced. Moreover, the use amount of the helium is reduced, so that the use amount of the argon is relatively increased, and the heat conduction performance of the argon is not the same as that of the helium, so that the temperature in the furnace body is the same, the electric power required by the exhaust mode of the embodiment of the application is about 2kw less than that required by the existing lower exhaust, and the energy is saved.

Preferably, the flow rate of helium is twice the flow rate of argon.

According to the practical situation, the gas flow of helium is set to be 5-8L/min, and the gas flow of argon is set to be 2-4L/min. Because the heat conduction of helium is larger than that of argon, a part of mixed gas of helium and argon is exhausted upwards, and the argon mainly plays a role in preserving the heat of the heating zone 10 of the optical fiber preform; a portion of the gas is vented downward and helium gas mainly serves to cool the molded optical fiber; on the basis of the helium quantity needs to be saved, the heat preservation effect of the optical fiber preform heating area 10 is satisfied, the cooling effect of the optical fiber forming area 11 is satisfied, and therefore the helium and argon quantity meeting the requirements is needed to be found.

Further, referring to fig. 3, the dashed arrows indicate the flow direction of the second gas. The optical fiber drawing furnace also comprises a separation hood 3 and a second air inlet 4, wherein the separation hood 3 is positioned in the optical fiber forming area 11 and divides the optical fiber forming area 11 into a first air flow channel 110 positioned on the outer side of the separation hood 3 and a second air flow channel 111 positioned on the inner side of the separation hood 3; the second air flow passage 111 communicates with the first air inlet 2; the second gas inlet 4 is communicated with the first gas flow passage 110, so that the second gas is introduced into the first gas flow passage 110 and is discharged from the gas outlet 12 at the upper end of the drawing furnace body 1.

After the separating cover 3 is added, the optical fiber forming area 11 is separated into two air flow channels, the first air flow channel 110 is used for the circulation of the first air, the second air flow channel 111 is used for the circulation of the second air, and the second air is directly discharged from the exhaust port 12 at the upper end of the drawing furnace body 1 so as to take away impurities such as dust and the like in the optical fiber production process.

Further, the second gas is argon.

Since helium mainly functions as a shielding gas and it is necessary to discharge impurities in the furnace body in order to reduce the amount of helium used, the above-mentioned effects can be achieved by designing the second gas as argon. Moreover, the heat conductivity of argon is inferior to that of helium, so that the argon can play a good heat preservation effect on the heating zone 10 of the optical fiber preform, and the electric power required by heating is greatly reduced.

Further, the second gas has a gas flow rate equal to the gas flow rate of the first gas.

The embodiment of the application designs that the airflow of the second gas is equal to the airflow of the first gas, so that the heat dissipation and the protection effect of the heating body reach the optimal balance, and the optimal effect is achieved by using the minimum helium.

Optionally, the optical fiber drawing furnace further comprises a vacuum pump, wherein the vacuum pump is communicated with an exhaust port 12 at the upper end of the drawing furnace body 1 and used for exhausting air from the exhaust port 12.

The vacuum pump is used for adjusting the gas exhaust rate and timely pumping away oxides in the furnace, so that the cleanness of the inside of the wire drawing furnace is ensured, and the attenuation quality level of the optical fiber is improved. The upper end of the wire drawing furnace body 1 is further provided with an upper seal, helium or argon is introduced into the upper seal to seal the wire drawing furnace body 1 in an air-tight manner, and the gas introduced into the wire drawing furnace body 1 from the upper seal is pumped out from the exhaust port 12 along with the first gas and the second gas by the vacuum pump.

Optionally, the optical fiber drawing furnace further includes a guiding structure 5, the guiding structure 5 is located at a boundary between the optical fiber preform heating zone 10 and the optical fiber forming zone 11, and the guiding structure 5 is configured to guide the first gas in the optical fiber forming zone 11 to the optical fiber preform heating zone 10.

Because the diameter in the prefabricated optical fiber pole zone of heating 10 is greater than the diameter in prefabricated optical fiber pole zone of heating 11, prefabricated optical fiber pole zone of heating 10 and the demarcation department of prefabricated optical fiber pole zone of heating 11 form a step, from the air current in the prefabricated optical fiber pole zone of heating 10 that flows in the prefabricated optical fiber pole zone of heating 11, form easily in step department and detain, and the impurity that produces also easily gathers in step department in the optical fiber production process, consequently, set up water conservancy diversion structure 5 in step department, guide the first gas in the prefabricated optical fiber pole zone of heating 11 smoothly to the prefabricated optical fiber pole zone of heating 10 in, and discharge, prevent the air current. And the first gas flowing upwards forms laminar flow clinging to the inner wall of the flow guide structure 5 at the position of the flow guide structure 5, so that stable laminar flow can still exist in the wire drawing furnace after the usage amount of helium is reduced, and the diameter of the optical fiber is ensured to be stable in the wire drawing process.

Preferably, the inner wall of the flow guiding structure 5 presents a guiding surface 50 sloping downwards.

One end of the flow guide structure 5 is connected with the wall surface of the optical fiber forming area 11, and the other end is obliquely arranged on the inner wall of the optical fiber forming area 11, so that the first gas flowing upwards is guided into the heating area 10 of the optical fiber perform, and meanwhile, the backflow of the first gas flowing upwards is also avoided.

Optionally, the optical fiber drawing furnace further comprises an extension pipe 6, wherein the extension pipe 6 is arranged at the bottom end of the drawing furnace body 1 and communicated with the optical fiber forming area 11; and the exhaust port 12 positioned at the bottom end of the wire drawing furnace body 1 is arranged on the extension pipe 6.

The length of the extension tube 6 can be adjusted according to requirements, the annealing time of the optical fiber is guaranteed, and the warping degree scrapping problem is solved. One end of the extension tube 6 is provided with a lower seal, helium is introduced into the lower seal to seal the furnace body in an air way, so that the cooling effect of the optical fiber is not influenced.

In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.