A sealing device for an optical fiber preform tail and a method thereof

Abstract

The application provides a sealing device and method suitable for a fiber preform tail handle, comprising: a fiber preform and a hanging rod tail pipe, a tail handle is arranged between the fiber preform and the hanging rod tail pipe, a fiber preform loose body variable diameter area is arranged on one end of the fiber preform close to the tail handle, a sealing assembly is arranged between the fiber preform and the hanging rod tail pipe, and the outer diameters of the sealing assembly, the fiber preform and the hanging rod tail pipe are equal; the sealing assembly is fully sealed, air can be effectively prevented from entering the drawing furnace through the tail handle, the fiber preform, the fiber preform loose body variable diameter area and the hanging rod tail pipe, the stability of airflow and temperature field in the drawing furnace is prevented from being disturbed, oxidation of the drawing furnace is avoided, and the quality of the fiber product is improved.

Description

Technical Field

[0001] This invention relates to the field of optical fiber manufacturing technology, and specifically to a sealing device and method for the tail shank of an optical fiber preform. Background Technology

[0002] Optical fiber is produced by heating and softening optical fiber preforms in an optical fiber drawing furnace, then drawing the preforms, which have an initial tail, into fibers. The optical fiber drawing furnace uses graphite heating elements. To protect the graphite components and ensure their proper functioning at high temperatures, a protective gas, typically an inert gas such as argon or helium, needs to be introduced into the furnace. Simultaneously, the entry of outside air into the furnace must be controlled to prevent the graphite components from burning out. After production, the preform typically has a gradually tapering tail.

[0003] Currently, although there are technologies that use sealing devices to seal the diameter-changing area of ​​the fiber optic tailstock, the diameter difference between the fiber optic tailstock, fiber preform, the diameter-changing area of ​​the fiber preform loose body, and the tail tube is large, making it impossible to achieve a complete seal. Air can still enter the drawing furnace through these areas, interfering with the stability of the airflow and temperature field inside the furnace, leading to oxidation of the drawing furnace and affecting the quality of optical fiber products. Summary of the Invention

[0004] To address the technical problem of preventing air from entering the fiber drawing furnace through areas such as the tailstock, optical fiber preform, the diameter variation zone of the loose body of the optical fiber preform, and the tail tube of the hanging rod, thus interfering with the stability of the airflow and temperature field inside the furnace, this invention proposes a sealing device and method suitable for the tailstock of optical fiber preforms.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] This invention provides a sealing device suitable for the tail shank of an optical fiber preform, comprising: an optical fiber preform and a tail tube, wherein a tail shank is provided between the optical fiber preform and the tail tube, and a loose body diameter-changing region is provided on the end of the optical fiber preform near the tail shank. A sealing assembly is installed between the optical fiber preform and the tail tube, wherein the outer diameters of the sealing assembly, the optical fiber preform, and the tail tube are equal.

[0007] This invention provides a sealing device and method for the tailstock of optical fiber preforms. The sealing component provides a complete seal, which can effectively prevent air from entering the drawing furnace through the tailstock, optical fiber preform, the diameter variation area of ​​the loose body of the optical fiber preform, and the tail tube of the hanging rod, thus interfering with the stability of the airflow and temperature field in the drawing furnace, avoiding oxidation of the drawing furnace, and improving the quality of optical fiber products.

[0008] As a preferred technical solution, the sealing assembly includes: a quartz sleeve, the outer diameter of which is equal to the outer diameter of the optical fiber preform; a tail shank ring is provided on the tail shank, the outer diameter of which is smaller than the outer diameter of the optical fiber preform; one end wall of the quartz sleeve is fitted onto the tail shank near the tail shank ring; and one open end of the quartz sleeve is fitted onto the side wall of the loose body diameter-changing region of the optical fiber preform.

[0009] As a preferred technical solution, the sealing assembly includes: a quartz cotton strip, which seals and fills the gap between the end wall of the quartz sleeve and the tail tube of the hanging rod, and the outer diameter of the quartz cotton strip is equal to the outer diameter of the quartz sleeve.

[0010] As a preferred technical solution, the quartz cotton strip is disposed on the outside of the tail shank ring, and a gap is provided between the quartz cotton strip and the tail shank ring to prevent melting.

[0011] As a preferred technical solution, the quartz sleeve includes: a first quartz component and a second quartz component. The first quartz component has a groove on its end wall, and the second quartz component has a protrusion on its end wall. The protrusion and the groove cooperate with each other to enable the first quartz component and the second quartz component to be snapped together. After being snapped together, the first quartz component and the second quartz component are locked together by a locking quartz pin to form an integral quartz sleeve.

[0012] As a preferred technical solution, the quartz sleeve is provided with a plurality of anti-melting elements, and the plurality of anti-melting elements are sleeved on the tail shank.

[0013] As a preferred technical solution, the anti-melting element includes: at least two sets of quartz full-circular rings, which are arranged opposite to each other as a first quartz full-circular ring and a second quartz full-circular ring. The first quartz full-circular ring is disposed on the end of the fiber preform loose body diameter-changing region near the tailstock, and the second quartz full-circular ring is disposed near the end wall of the quartz sleeve. A plurality of quartz semi-circular rings are provided between the first quartz full-circular ring and the second quartz full-circular ring.

[0014] This application provides a sealing method for the tail shank of an optical fiber preform, comprising the following steps:

[0015] The optical fiber preform and one end of the tailstock are sealed to form the first sealing assembly.

[0016] The other end of the tailstock is sealed to the tail tube of the hanging rod to form a second sealing assembly;

[0017] The first sealing component corresponds to and cooperates with the second sealing component to seal the space between the optical fiber preform and the hanging rod tail tube.

[0018] As a preferred technical solution, sealing the optical fiber preform and one end of the tailstock to form a first sealing assembly includes the following steps:

[0019] Place the first quartz ring on the end of the fiber preform loose body near the tailstock in the variable diameter region.

[0020] Multiple quartz semi-circular rings are placed sequentially on the first full quartz ring;

[0021] Place a second full quartz ring on top of the semi-circular quartz ring;

[0022] One end of the lifting tailstock is installed on the tail tube of the hanging rod, and then the other end of the lifting tail tube is sequentially suspended into the first full quartz ring, the quartz semi-circular ring, and the second full quartz ring.

[0023] The protrusion of the second quartz piece is inserted into the groove of the first quartz piece to form the end wall of the quartz sleeve. The end wall of the quartz sleeve is installed on the second quartz full ring. The opening of the quartz sleeve is installed on the side wall of the fiber preform loose body diameter variation region near the end of the fiber preform.

[0024] As a preferred technical solution, sealing the other end of the tailstock with the tail tube of the hanging rod to form a second sealing assembly includes the following steps:

[0025] Sufficient quartz cotton strips are inserted into the gap between the tail tube of the hanging rod and the end wall of the quartz sleeve to seal the tail tube of the hanging rod.

[0026] The present invention provides a sealing device and method for the tail shank of an optical fiber preform, which has the following beneficial effects:

[0027] 1) The structure is reasonably designed. A sealing assembly is installed between the optical fiber preform and the hanging rod tail tube. The outer diameters of the sealing assembly, the optical fiber preform, and the hanging rod tail tube are equal. The sealing assembly provides a complete seal, which can effectively prevent air from entering the drawing furnace through the tail tube, optical fiber preform, the diameter variation area of ​​the loose body of the optical fiber preform, and the hanging rod tail tube, thus interfering with the stability of the airflow and temperature field in the drawing furnace, avoiding oxidation of the drawing furnace, and improving the quality of optical fiber products.

[0028] 2) The fiber preform and one end of the tail rod are sealed with a combination of quartz sleeves, quartz full rings and quartz semi-circular rings to form a first sealing assembly. The other end of the tail rod and the tail tube are sealed with quartz cotton strips to form a second sealing assembly. The first and second sealing assemblies work together to effectively prevent air from entering the drawing furnace through the tail rod, fiber preform, the diameter variation area of ​​the loose body of the fiber preform and the tail tube, which would interfere with the stability of the airflow and temperature field in the drawing furnace, prevent oxidation of the drawing furnace and improve the quality of the optical fiber products.

[0029] 3) The height of the quartz sleeve spans the diameter variation zone of the preformed rod porous body and part of the tail shank. The tail shank is provided with a tail shank ring. The tail shank ring ensures that the quartz sleeve can be fitted onto a certain length of the tail shank. During operation, the tail shank ring restricts the displacement of the quartz sleeve in the axial direction of the tail shank, improving the stability of the device. On the other hand, it prevents the end wall of the quartz sleeve from contacting the tail tube of the hanging rod and melting and connecting in the drawing furnace.

[0030] 4) The first full-circular quartz ring is disposed on the end of the fiber preform away from the fiber preform in the loose body diameter variation region. The second full-circular quartz ring is disposed near the end wall of the quartz sleeve. The quartz semi-circular ring is disposed between the first full-circular quartz ring and the second full-circular quartz ring. This improves the stability of the fused component structure and avoids the problem of poor structural stability and easy detachment during the production process caused by simply using quartz semi-circular rings for assembly. The quartz sleeve and the tail shank are separated by the full-circular quartz ring and the quartz semi-circular ring. The number of full-circular quartz rings and quartz semi-circular rings used is determined by the height of the tail shank. Their main function is to prevent the quartz sleeve and the lower edge of the quartz sleeve from being fused and connected to the fiber preform in the drawing furnace.

[0031] 5) The sealing components are fully sealed to effectively prevent air from entering the drawing furnace through the tailstock, fiber preform, the diameter variation area of ​​the loose body of the fiber preform, and the tail tube of the hanging rod, which would interfere with the stability of the airflow and temperature field in the drawing furnace, prevent oxidation of the drawing furnace, improve the utilization rate of raw materials and the life of the drawing equipment, and reduce the cost of optical fiber production. Attached Figure Description

[0032] Figure 1 A schematic diagram of a sealing device for the tail shank of an optical fiber preform provided by the present invention;

[0033] Figure 2 A partial structural schematic diagram of a sealing device suitable for the tail shank of an optical fiber preform provided by the present invention.

[0034] Figure 3 A schematic diagram of the structure of the quartz sleeve provided by the present invention;

[0035] Figure 4 This is a schematic diagram of the structure of the quartz semicircular ring provided by the present invention;

[0036] Figure 5 A schematic diagram of the structure of the quartz full-circle ring provided by the present invention.

[0037] Among them, 1-optical fiber preform; 2-optical fiber preform loose body diameter variation region; 3-tail shank; 31-tail shank ring; 4-quartz sleeve; 41-first quartz component; 411-groove; 42-second quartz component; 421-protrusion; 43-end wall of quartz sleeve; 5-quartz full ring; 51-first quartz full ring; 52-second quartz full ring; 6-quartz semi-circular ring; 7-quartz cotton strip; 8-hanging rod tail tube. Detailed Implementation

[0038] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0039] like Figure 1-2 As shown, the present invention provides a sealing device suitable for the tail shank of an optical fiber preform, comprising: an optical fiber preform 1 and a tail tube 8, wherein a tail shank 3 is provided between the optical fiber preform 1 and the tail tube 8, an optical fiber preform loose body diameter-changing region 2 is provided on one end of the optical fiber preform 1 near the tail shank 3, the other end of the tail shank 3 is connected to the tail tube 8, the axial cross-section of the other end of the tail shank 3 is trapezoidal, and a tail shank ring 31 is provided on the tail shank 3, the outer diameter of the tail shank ring 31 being smaller than that of the optical fiber preform. The outer diameter of rod 1, the end wall 43 of the quartz sleeve is fitted onto the end of the tail shank 3 near the tail shank ring 31, the axial section of the quartz sleeve 4 is inverted "U" shape, the open end of the quartz sleeve 4 is fitted onto the side wall of the variable diameter region 2 of the fiber preform, the quartz cotton strip 7 seals and fills the gap between the end wall 43 of the quartz sleeve and the tail tube 8 of the hanging rod, the outer diameter of the quartz cotton strip 7 is equal to the outer diameter of the quartz sleeve 4, and the quartz cotton strip 7 is set on the tail shank ring 31. On the outer side, a gap for preventing melting is provided between the quartz cotton strip 7 and the tail ring 31. Multiple anti-melting elements are provided inside the quartz sleeve 4, and these elements are sleeved on the tail ring 3. Each anti-melting element includes at least two sets of full quartz rings 5 ​​and several semi-circular quartz rings 6. The two sets of oppositely arranged full quartz rings 5 ​​are a first full quartz ring 51 and a second full quartz ring 52. The first full quartz ring 51 is located in the diameter variation region 2 of the loose body of the optical fiber preform near the tail ring. At one end of 3, the second quartz full-circle ring 52 is located near the end wall 43 of the quartz sleeve. Several quartz semi-circle rings 6 are provided between the first quartz full-circle ring 51 and the second quartz full-circle ring 52. The sealing assembly provides a complete seal, which can effectively prevent air from entering the drawing furnace through the tail shank 3, optical fiber preform 1, optical fiber preform loose body diameter change area 2 and hanging tail tube 8, thus interfering with the stability of airflow and temperature field in the drawing furnace, avoiding oxidation of the drawing furnace, and improving the quality of optical fiber products.

[0040] like Figure 3As shown, the quartz sleeve 4 provided by the present invention includes: a first quartz element 41 and a second quartz element 42. A groove 411 is formed on the end wall of the first quartz element 41, and a protrusion 421 is formed on the end wall of the second quartz element 42. The protrusion 421 and the groove 411 cooperate to achieve a snap-fit ​​connection between the first quartz element 41 and the second quartz element 42. After snap-fit, the first quartz element 41 and the second quartz element 42 are locked together by a locking quartz pin (not shown) to form an integral quartz sleeve 4. Operation is convenient. For ease of implementation, the quartz sleeve 4 has an assembly structure, which facilitates the installation of the full quartz ring 5 and the semi-circular quartz ring 6 inside the quartz sleeve 4. On the other hand, the protrusion 421 and the groove 411 cooperate with each other to enable the first quartz piece 41 and the second quartz piece 42 to be snapped together. After snapping together, the first quartz piece 41 and the second quartz piece 42 are locked together by a locking quartz pin (not shown) to form an integral quartz sleeve 4. This structure of the quartz sleeve 4 improves the stability of the quartz sleeve during the optical fiber production process and effectively prevents the quartz sleeve from falling off.

[0041] like Figure 4-5 The anti-melting component includes at least two sets of quartz full-circular rings 5, which are arranged opposite to each other as a first quartz full-circular ring 51 and a second quartz full-circular ring 52. The first quartz full-circular ring 51 is disposed on the end of the fiber preform loose body diameter variation region 2 near the tail shank 3, and the second quartz full-circular ring 52 is disposed near the end wall 43 of the quartz sleeve. A plurality of quartz semi-circular rings 6 are provided between the first quartz full-circular ring and the second quartz full-circular ring 52, which improves the stability of the anti-melting component structure and avoids the need to assemble using only quartz semi-circular rings 6. During the production process, problems such as poor structural stability and easy detachment occur. Quartz full-circle ring 5 and quartz semi-circle ring 6 are used to separate quartz sleeve 4 from tail shank 3. The number of quartz full-circle rings 5 ​​and quartz semi-circle rings 6 used is determined by the length of tail shank 3. Their main function is to prevent quartz sleeve 4 and its lower edge from melting and connecting with optical fiber preform 1 in the drawing furnace. The quartz full-circle ring 5 has a circular tail shank through hole in the center to facilitate the passage of tail shank 3, and the quartz semi-circle ring 6 has a semi-circular through hole to facilitate the passage of tail shank 3, which facilitates the installation of quartz full-circle ring 5 and quartz semi-circle ring 6.

[0042] This application provides a sealing method for the tail shank of an optical fiber preform, comprising the following steps:

[0043] First, place the first full quartz ring 51 stably on one end of the loose body variable diameter area 2 near the tail shank 3. Then, place multiple quartz semi-circular rings 6 on the first full quartz ring 51 in sequence until a certain height is reached.

[0044] A second full quartz ring 52 is placed on the quartz semi-circular ring 6, and the second full quartz ring 52 is located near the end wall 43 of the quartz sleeve.

[0045] The tail shank 3 is installed on the tail tube 8 of the hanging rod, and then the tail tube 8 of the hanging rod is suspended in sequence into the first full quartz ring 51, the half quartz ring 6 and the second full quartz ring 52.

[0046] The protrusion 421 of the second quartz piece 41 is inserted into the groove 411 of the first quartz piece 41 to form the end wall 43 of the quartz sleeve. The end wall 43 of the quartz sleeve is installed on the second quartz full ring 52, and the first quartz piece 41 and the second quartz piece 42 are locked together with a locking quartz pin (not shown) to form an integral quartz sleeve 4. The opening of the quartz sleeve 4 is installed on the side wall of the fiber preform loose body diameter variation region 2 near the end of the fiber preform 1.

[0047] Sufficient quartz cotton strips 7 are inserted into the gap between the tail tube 8 of the hanging rod and the end wall 43 of the quartz sleeve to seal the tail tube 8 of the hanging rod.

[0048] A sealing assembly with an outer diameter matching that of the optical fiber preform 1 and the hanging rod tail tube 8 is formed, thus completing the sealing of the original tail of the optical fiber preform. The sealing assembly provides a complete seal, which can effectively prevent air from entering the drawing furnace through the tail tube 3, optical fiber preform 1, the diameter variation area 2 of the loose body of the optical fiber preform, and the hanging rod tail tube 8, thus interfering with the stability of the airflow and temperature field in the furnace, avoiding oxidation of the drawing furnace, and improving the quality of optical fiber products.

[0049] The present invention provides a sealing device and method for the tail shank of an optical fiber preform, which has the following beneficial effects:

[0050] 1) The structure is reasonably designed. A sealing assembly is installed between the optical fiber preform 1 and the hanging rod tail tube 8. The outer diameters of the sealing assembly, the optical fiber preform 1, and the hanging rod tail tube 8 are equal. The sealing assembly provides a complete seal, which can effectively prevent air from entering the drawing furnace through the tail shank 3, the optical fiber preform 1, the diameter variation area 2 of the loose body of the optical fiber preform, and the hanging rod tail tube 8, thus interfering with the stability of the airflow and temperature field in the drawing furnace, avoiding oxidation of the drawing furnace, and improving the quality of optical fiber products.

[0051] 2) The optical fiber preform 1 and one end of the tail shank 3 are sealed with a combination of a quartz sleeve 4, a quartz full-circular ring 5, and a quartz semi-circular ring 6 to form a first sealing assembly. The other end of the tail shank 3 and the hanging rod tail tube 8 are sealed with a quartz cotton strip 7 to form a second sealing assembly. The first sealing assembly and the second sealing assembly work together to effectively prevent air from entering the drawing furnace through the tail shank 3, the optical fiber preform, the diameter variation area 2 of the loose body of the optical fiber preform, and the hanging rod tail tube 8, which would interfere with the stability of the airflow and temperature field in the drawing furnace, avoid oxidation of the drawing furnace, and improve the quality of the optical fiber products.

[0052] 3) The height of the quartz sleeve 4 spans the diameter variation zone 2 of the preformed rod porous body and part of the tail shank 3. The tail shank 3 is provided with a tail shank ring 31. The tail shank ring 31 ensures that the quartz sleeve 4 can be sleeved on a certain length of part of the tail shank 3. During the operation, the tail shank ring 31 restricts the displacement of the quartz sleeve 4 in the axial direction of the tail shank 3, improving the stability of the device. On the other hand, it prevents the end wall 43 of the quartz sleeve from contacting the hanging rod tail tube 8 and melting and connecting in the drawing furnace.

[0053] 4) The first full-circular quartz ring 51 is disposed on the end of the fiber preform loose body variable diameter region 2 away from the fiber preform 1, the second full-circular quartz ring 52 is disposed near the end wall 43 of the quartz sleeve, and the quartz semi-circular ring 6 is disposed between the first full-circular quartz ring 51 and the second full-circular quartz ring 52. This improves the stability of the fused part structure and avoids the problem of poor structural stability and easy detachment during the production process caused by simply using quartz semi-circular rings for assembly. The quartz sleeve 4 and the tail shank 3 are separated by the full-circular quartz ring 5 and the semi-circular quartz ring 6. The number of full-circular quartz rings 5 ​​and the semi-circular quartz ring 6 used is determined by the height of the tail shank 3. Their main function is to prevent the quartz sleeve 4 and the lower edge of the quartz sleeve 4 from being fused and connected to the fiber preform 1 in the drawing furnace.

[0054] 5) The sealing components are fully sealed to effectively prevent air from entering the drawing furnace through the tail shank 3, optical fiber preform 1, optical fiber preform loose body diameter change area 2 and hanging tail tube 8, which would interfere with the stability of airflow and temperature field in the drawing furnace, avoid oxidation of the drawing furnace, improve the utilization rate of raw materials and the life of drawing equipment, and reduce the cost of optical fiber production.

[0055] It is understood that this invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are protected by this invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of this invention.

Claims

1. A sealing device suitable for the tail shank of an optical fiber preform, characterized in that, include: The optical fiber preform and the hanging rod tail tube are provided with a tail shank between the optical fiber preform and the hanging rod tail tube. The optical fiber preform has a loose body diameter-changing area near the tail shank. A sealing assembly is installed between the optical fiber preform and the hanging rod tail tube. The outer diameters of the sealing assembly, the optical fiber preform and the hanging rod tail tube are equal. The sealing assembly includes: a quartz sleeve, the outer diameter of which is equal to the outer diameter of the optical fiber preform; a tail shank ring is provided on the tail shank, the outer diameter of which is smaller than the outer diameter of the optical fiber preform; one end wall of the quartz sleeve is fitted onto the tail shank near the tail shank ring; and one open end of the quartz sleeve is fitted onto the side wall of the loose body diameter-changing region of the optical fiber preform. The sealing assembly includes: a quartz cotton strip, which is used to seal and fill the gap between the end wall of the quartz sleeve and the tail tube of the hanging rod, and the outer diameter of the quartz cotton strip is equal to the outer diameter of the quartz sleeve; The quartz cotton strip is disposed on the outside of the tail shank ring, and a gap is provided between the quartz cotton strip and the tail shank ring to prevent melting; The quartz sleeve includes: a first quartz piece and a second quartz piece. The first quartz piece has a groove on its end wall, and the second quartz piece has a protrusion on its end wall. The protrusion and the groove cooperate with each other to enable the first quartz piece and the second quartz piece to be snapped together. After being snapped together, the first quartz piece and the second quartz piece are locked together by a locking quartz pin to form an integral quartz sleeve. The quartz sleeve is provided with a plurality of anti-melting elements, and the plurality of anti-melting elements are sleeved on the tail shank; The anti-melting element includes at least two sets of quartz full-circular rings, which are arranged opposite to each other as a first quartz full-circular ring and a second quartz full-circular ring. The first quartz full-circular ring is disposed on the end of the fiber preform loose body diameter variation region near the tail shank, and the second quartz full-circular ring is disposed near the end wall of the quartz sleeve. A plurality of quartz semi-circular rings are provided between the first quartz full-circular ring and the second quartz full-circular ring.

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