An injection pipe device and equipment for high-temperature doping and rod making by gas phase method

Abstract

The present invention discloses an injection pipe device and equipment for high-temperature doping rod making by gas phase method. The injection pipe device includes a gas delivery pipe and a heating temperature measuring rod built in a thermal insulation sleeve. The thermal insulation sleeve is arranged in a high-purity quartz sleeve, and the gas delivery pipe is made of corrosion-resistant stainless steel. A device for high-temperature doping rods by gas phase method includes the above-mentioned injection pipe device, the output end of the injection pipe device is configured with a reaction tube and a lathe rod making system, and the input end of the injection pipe device is configured with a high-temperature doping system. The heating and temperature measuring rod provided by the present invention are in direct contact with multiple gas delivery pipes, which improves the thermal conductivity. At the same time, the external thermal insulation pipe, when the heating and temperature measuring rods are raised to a set temperature of 200°C or above, the gas delivery pipe will be heated more evenly and the temperature field will be more stable. It will not condense and produce crystals due to uneven temperature in the thermal insulation pipe, thereby improving the production efficiency of the gas delivery pipe and saving maintenance time and cost.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber cable preparation, and in particular to an injection tube device and equipment used for high-temperature doping rod making by a vapor phase method. Background Art

[0002] With the rapid development of global laser technology, the product lines of various categories of lasers have gradually improved, and laser processing has penetrated into all areas of the manufacturing industry. Laser types include gas lasers, liquid lasers, solid lasers, semiconductor lasers, and fiber lasers. Compared with other lasers, fiber lasers have obvious advantages in maintenance costs, maximum output power, electro-optical conversion rate, pump life, stability, and flexible processing. Fiber laser machines can be used in many industries such as microelectronics, printing, automobiles, medical equipment, shipbuilding, and aviation. The processable materials range from micromachining of heart stents and computer memory chips to deep fusion welding of thick pipe walls. Flexible operation is one of the most revolutionary features of fiber lasers, and they can be easily integrated into multi-axis robots and galvanometer systems.

[0003] Fiber lasers are mainly composed of pump sources, couplers, rare earth-doped optical fibers, resonant cavities and other components, among which rare earth-doped optical fibers account for nearly 12% of the total cost of fiber lasers. Many domestic companies mostly purchase imported rare earth-doped optical fibers. In recent years, the continuous advancement of domestic substitution for imports has also stimulated domestic companies' investment in the field of rare earth-doped optical fibers. Among them, import substitution has been completed in the low-power field, and the substitution process is accelerating in the medium-power field, while the localization rate in the high-power field is steadily increasing. Domestic substitution for imports is in full swing.

[0004] The MCVD method for preparing rare earth-doped optical fiber preforms is mainly divided into liquid phase doping method and gas phase doping method. The liquid phase doping method is the earliest process method used to prepare rare earth-doped optical fiber preforms. It deposits a loosely structured deposition layer on the inner wall of the reaction tube through the MCVD process, and immerses this loosely structured deposition layer in a solution containing rare earth ions, so that the deposition layer absorbs the rare earth ions in the solution, and then the rare earth ions are doped into the reaction tube through dehydration, vitrification and other processes. The gas phase doping method is a process method developed in recent years. It deposits the cladding through the MCVD process, but the deposition of the rare earth material in the core area is to bring the rare earth chelate or rare earth chloride containing rare earth elements into the MCVD reaction tube in the form of gas. Under the action of the heat source outside the tube, it produces an oxidation reaction with the silicon, phosphorus, etc. introduced by the MCVD, migrates and deposits on the inner wall of the reaction tube, and directly forms a doped core area. Compared with the liquid phase doping method, the gas phase doping method has a simpler process, the profile of the deposited preform is finer, the doping concentration can be flexibly controlled, the uniformity is good, and the core diameter can be large or small.

[0005] In the existing injection pipe device used for the vapor phase high temperature doping rod making equipment (MCVD equipment), heating is performed by wrapping a heating belt around the outside of the metal thermal insulation sleeve. This can easily lead to uneven temperature inside the metal thermal insulation sleeve, which can cause condensation and crystallization and block the pipeline, thereby affecting production efficiency. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide an injection pipe device and equipment for high-temperature doping and rod making by the vapor phase method with more uniform heating in view of the deficiencies in the above-mentioned prior art.

[0007] The technical solution adopted by the present invention is: an injection pipe device for high-temperature doping and rod making by the vapor phase method, characterized in that it includes a gas delivery pipe and a heating temperature measuring rod built into a thermal insulation casing, the thermal insulation casing is arranged in a high-purity quartz casing, and the gas delivery pipe is made of corrosion-resistant stainless steel.

[0008] According to the above technical solution, the heating temperature measuring rod is arranged in the middle position of the thermal insulation sleeve, and there are at least two gas delivery pipes arranged on the periphery of the heating temperature measuring rod.

[0009] According to the above technical solution, the thermal insulation sleeve includes a metal sleeve and a thermal insulation layer coated outside the metal sleeve.

[0010] According to the above technical solution, the thickness of the thermal insulation layer is 1 to 1.3 mm.

[0011] According to the above technical solution, the thermal insulation layer is a high temperature resistant tape.

[0012] According to the above technical solution, the output end of the raw material delivery pipe passes through the sealing element

[0013] The sealing element is introduced into the reaction tube, and the outer periphery of the sealing element is sealed with the inner wall of the high-purity quartz sleeve.

[0014] According to the above technical solution, the sealing element is a perfluororubber sealing block.

[0015] A device for high-temperature doping and rod making by the vapor phase method, characterized in that it includes the injection tube device as described above, wherein the output end of the injection tube device is configured with the reaction tube and the lathe rod making system, and the input end of the injection tube device is configured with the high-temperature doping system.

[0016] According to the above technical solution, the injection tube device is supported and fixed by the gas end rotary sealing device, and the reaction tube is rotary sealed by the rotary sealing device and the chucks at both ends.

[0017] The beneficial effects achieved by the present invention are:

[0018] 1. The heating and temperature measuring rods provided by the present invention are in direct contact with multiple gas delivery pipes, which improves the heat conduction efficiency. At the same time, an external thermal insulation pipe is provided. After the heating and temperature measuring rods are raised to a set temperature of above 200°C, the gas delivery pipes will be heated more evenly and the temperature field will be more stable. Crystallization will not be condensed due to uneven temperature in the thermal insulation pipes, thereby improving the production efficiency of the gas delivery pipes and saving maintenance time and costs.

[0019] 2. The present invention integrates the temperature measuring unit into the heating rod, which reduces the temperature measuring thermocouple unit compared to the previous method of injecting a thermometer into a metal sleeve, thereby saving more installation space to increase the thickness of the insulation layer and improve the insulation effect;

[0020] 3. The metal casing and gas delivery pipe of the present invention are both made of corrosion-resistant stainless steel, so that they can withstand the corrosiveness of the reaction gas and have a longer service life;

[0021] 4. The gas delivery tube of the present invention is placed in the reaction tube through a sealing element, which ensures the sealing of the tail end of the thermal insulation tube to prevent the gas from flowing back into the high-purity quartz tube during the preparation of the preform rod, thereby corroding the thermal insulation tube and the gas delivery tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A structural diagram of an injection tube device for high-temperature doping and rod making by a vapor phase method provided in an embodiment of the present invention.

[0023] Figure 2 for Figure 1 AA direction schematic diagram.

[0024] Figure 3 A schematic structural diagram of a device for high-temperature doping and rod making by a vapor phase method provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings.

[0026] like Figure 1 , 2As shown, this embodiment provides an injection pipe device for high-temperature doping rod making by gas phase method, including a gas delivery pipe 5 and a heating temperature measuring rod 4 built in a thermal insulation sleeve, the thermal insulation sleeve is arranged in a high-purity quartz sleeve 1, the gas delivery pipe 5 is made of corrosion-resistant stainless steel, specifically a stainless steel pipe or an alloy pipe, the heating unit of the heating temperature measuring rod is made of a heating wire, the resistance value of the heating wire can be selected according to the required heating temperature, and it is convenient to adjust the voltage to accurately control the temperature of the heating rod during use; the built-in temperature measuring unit uses a K-type thermocouple. Among them, the heating temperature measuring rod 4 is arranged in the middle position of the thermal insulation sleeve, and there are at least two gas delivery pipes 5, which are arranged on the periphery of the heating temperature measuring rod. This embodiment is described by taking three gas delivery pipes 5 as an example, and the three gas delivery pipes 5 are evenly arranged on the periphery of the heating temperature measuring rod 4. The present invention improves the heat conduction efficiency by arranging a heating and temperature measuring rod 4 in direct contact with multiple gas delivery pipes 5. At the same time, an external thermal insulation pipe is arranged. After the heating and temperature measuring rod rises to a set temperature of above 200°C, the gas delivery pipe will be heated more evenly and the temperature field will be more stable. Crystallization will not be condensed due to uneven temperature in the thermal insulation pipe, thereby improving the production efficiency of the gas delivery pipe and saving maintenance time and cost.

[0027] In this embodiment, the thermal insulation sleeve includes a metal sleeve 2 and an insulation layer 3 coated on the outside of the metal sleeve. The thickness of the insulation layer is 1.2 mm. The insulation layer is a high temperature resistant tape. The high temperature resistant tape has an insulation effect on the metal sleeve 2, and the temperature of the high temperature steam above 200°C passing through the gas delivery pipe 5 will not be reduced due to the rapid cooling of the metal sleeve 2 in contact with the air, and at the same time, a relatively stable temperature field is formed in the metal sleeve 2. In the specific implementation, the high temperature resistant tape is evenly wrapped around the metal sleeve 2. During the implementation process, the tape is observed to have no wrinkles, so that the metal sleeve 2 can be injected into the high purity quartz sleeve 1. After the metal sleeve 2 is injected into the high purity quartz tube 1, observe whether the metal sleeve 2 is loose. Too large a gap will affect the service life of the high purity quartz tube 1. The metal sleeve is a stainless steel sleeve.

[0028] When the raw material delivery tube is configured with the reaction tube 7, the output end of the gas delivery tube 5 passes through the sealing element 6 and enters the reaction tube, and the outer periphery of the sealing element is sealed with the inner wall of the high-purity quartz sleeve 1. In this embodiment, the sealing element 6 is a perfluororubber sealing block. The high-purity quartz tube 1 and the perfluororubber sealing block wrap and seal the metal sleeve 2 and the gas delivery tube 5, so that the metal sleeve 2 and the gas delivery tube 5 are isolated from the chemical reaction environment of the injected reaction tube 7, and are not backflowed and corroded by the acidic gas in the environment.

[0029] After inserting the heating temperature measuring rod 4 and the three gas delivery tubes 5 into the metal sleeve 2 and adjusting the position, ensure that the gas delivery tube 5 has an extra distance of 1.5 cm to facilitate the installation of the perfluororubber sealing block, and ensure the sealing of the right end of the metal sleeve 2 to prevent the gas from flowing back into the high-purity quartz tube 1 during the preparation of the preform rod, corroding the metal sleeve 2 and the gas delivery tube 5; in order to facilitate the positioning of the perfluororubber block, the gap between the gas delivery tube 5 and the metal sleeve 2 is generally 0.1-0.3mm to prevent the gap from being too large and causing the gas delivery tube 5 to shake in the metal sleeve 2. In addition, in actual operation, in order to ensure that the opening of the perfluororubber sealing block can be accurately aligned with the gas delivery tube 5, it is necessary to use a tooling rod to adjust the position of the gas delivery tube 5.

[0030] like Figure 3 As shown, this embodiment also provides a high-temperature doping rod making device for the gas phase method, including the injection pipe device 10 as described above, the output end of the injection pipe device 10 is configured with the reaction tube 7 and the lathe rod making system 11, and the input end of the injection pipe device is configured with the high-temperature doping system 9, wherein the injection pipe device 10 is supported and fixed by the gas end rotary sealing device 12, and the reaction tube 7 is rotated and sealed with the chucks at both ends by the rotary sealing device 12. Among them, the high-temperature doping system, the gas end rotary sealing device 12, and the lathe rod making system 11 are all prior arts. When it is necessary to produce a preform doped with rare earth elements, the mixed gas doped with rare earth elements enters the reaction tube 7 through the injection pipe device 10, and a deposition reaction occurs in the heating zone. During production, the production process personnel can control the gas flow rate of the mass flowmeter MFC in the high-temperature doping system 9, the operating speed of the burner in the lathe rod making system 11, and the rotation speed of the reaction tube 7 according to the formula according to the preform doped with rare earth elements to be produced.

[0031] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An injection pipe device for high-temperature doping and rod making by vapor phase method, characterized in that: It includes a gas delivery pipe and a heating temperature measuring rod built into a thermal insulation sleeve, the thermal insulation sleeve is arranged in a high-purity quartz sleeve, and the gas delivery pipe is made of corrosion-resistant stainless steel; The heating temperature measuring rod is arranged in the middle of the heat-insulating sleeve, and there are at least two gas delivery pipes, which are arranged at equal intervals on the periphery of the heating temperature measuring rod and are in direct contact with the heating temperature measuring rod; The thermal insulation sleeve comprises a metal sleeve and a thermal insulation layer coated outside the metal sleeve.

2. The injection pipe device for high temperature doping rod making by vapor phase method according to claim 1, characterized in that: The thickness of the thermal insulation layer is 1 to 1.3 mm.

3. The injection pipe device for high temperature doping rod making by vapor phase method according to claim 1, characterized in that: The thermal insulation layer is a high temperature resistant adhesive tape.

4. The injection pipe device for high temperature doping rod making by vapor phase method according to claim 1, characterized in that: The output end of the raw material delivery tube passes through the sealing element and enters the reaction tube. The outer periphery of the sealing element is sealed with the inner wall of the high-purity quartz sleeve.

5. The injection pipe device for high temperature doping rod making by vapor phase method according to claim 4, characterized in that: The sealing element is a perfluororubber sealing block.

6. A device for high temperature doping rods by vapor phase method, characterized in that: It comprises the injection tube device as described in any one of claims 1 to 5, wherein the output end of the injection tube device is configured with the reaction tube and the lathe rod making system, and the input end of the injection tube device is configured with the high-temperature doping system.

7. The device for high temperature doping rods by vapor phase method according to claim 6, characterized in that: The injection pipe device is supported and fixed by a gas end rotary sealing device, and the reaction tube is rotary sealed by clamping the rotary sealing device with the chucks at both ends.

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