Non-equal-ratio quartz glass pipe drawing device and method
By using adjustable pressure gas source and air pressure buffer device in the drawing device of quartz glass pipe, adjusting the ratio of the outer diameter and pore diameter of the pipe, the existing problem of melting and shrinking pulling is difficult to meet the requirements of different specifications, and achieves the problem of the existing ratio of melting and shrinking pulling. High precision non-equal quartz glass pipe drawing.
Patent Information
- Application Number
- CN202411236666.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-04
- Publication Date
- 2025-01-03
AI Technical Summary
The current quartz glass pipe is difficult to meet the demand for pipe diameter ratios of different specifications in actual use, especially the demand for optical fiber prefabricated rods.
A non-equal quartz glass pipe is designed. By setting a sealed end cap on a graphite furnace to communicate with an adjustable pressure gas source and an air pressure buffer device, the ratio of the outer diameter and the aperture of the pipe is adjusted by using the air pressure difference. Achieve non-equal melt drawing.
This device can effectively control the pore size ratio of quartz glass pipes, improve processing function and flexibility, prevent pollution in high-temperature zones, alleviate gas pressure fluctuations, improve pulling accuracy, and meet the needs of pipe diameters of different specifications.
Smart Images
Figure CN119241051A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a device and a method for drawing a non-isotropic quartz glass tube, belonging to the technical field of quartz glass tube preparation. Background Art
[0002] Most of the existing quartz glass tubes of various specifications are made of larger quartz glass tubes through high-temperature melting and drawing. High-temperature melting and drawing is a contactless drawing process. During the melting and drawing process, when the pressure inside and outside the tube is the same, the outer diameter and aperture of the drawn quartz glass tube are reduced, but the ratio of the outer diameter to the aperture is the same as that of the tube before drawing, which is usually called constant ratio melting and shrinking. Although the constant ratio melting and shrinking drawing process is relatively simple and stable, the aperture ratio is determined by the parent material, which is often difficult to meet the actual use requirements, especially the actual use of optical fiber preform rods. Summary of the invention
[0003] The technical problem to be solved by the present invention is to provide a non-proportional quartz glass tube drawing device and method in view of the deficiencies of the above-mentioned prior art, which can adjust the ratio of outer diameter to aperture and draw quartz glass tubes with different specifications and diameter ratios.
[0004] The technical solution of the drawing device adopted by the present invention to solve the above-mentioned problems is: it includes a graphite furnace, a clamping mechanism is correspondingly arranged above the graphite furnace, the clamping mechanism is connected to the lifting and feeding device, and a traction wheel is correspondingly arranged below the graphite furnace. It is characterized in that a sealing end cover is arranged to be configured with the upper end of the mother glass tube, and the sealing end cover is connected to the pressure regulating gas source through a pipeline and is connected to the air pressure buffer device.
[0005] According to the above scheme, a small sealing cover is provided which is arranged at the lower end of the processed quartz glass tube.
[0006] According to the above scheme, the pressure regulating gas source is a pure gas adjustable pressure gas source, and the pressure of the adjustable pressure gas source is higher than the atmospheric pressure.
[0007] According to the above scheme, the air pressure buffer device includes a U-shaped cavity, one end of the U-shaped cavity is sealed, the other end is open, and the lower end has a bottom cavity that connects the two sides. The U-shaped cavity is filled with liquid that is higher than the bottom cavity, and a buffer interface is arranged above one side of the sealed end of the U-shaped cavity to communicate with the sealed end cover pipeline, and the other end of the U-shaped cavity is open to communicate with the outside world.
[0008] According to the above scheme, the height of the liquid level in the U-shaped cavity is 1 / 3 to 2 / 3 of the height of the entire U-shaped cavity, and the buffer interface is always higher than the liquid level of the liquid in the U-shaped cavity.
[0009] According to the above scheme, the adjustable pressure gas source is connected in series with a flow controller MFC and is also connected in parallel with a pressure gauge.
[0010] According to the above scheme, a pressure regulating and relief valve is connected next to the adjustable pressure gas source.
[0011] The technical solution of the fused-drawing method of the quartz glass tube of the present invention is:
[0012] The upper end of the mother glass tube is clamped on the graphite furnace through a clamping mechanism, and the lower part of the mother glass tube enters the furnace cavity of the graphite furnace. A sealing end cap is installed on the upper end surface of the mother glass tube, and the cavity of the mother glass tube is connected with the adjustable pressure gas source and the gas pressure buffer device through a pipeline. The mother glass tube entering the furnace cavity is heated by the graphite furnace, and the heating temperature is above 1500°C. A protective gas is passed through the graphite furnace to prevent the graphite furnace from oxidation. At the same time, the adjustable pressure gas source is opened to melt the mother glass tube and thin it and extend downward. The glass tube assembly extending downward cools and hardens and enters the traction wheel. A small sealing cap is installed on the lower end of the processed quartz glass tube, so that the internal cavity of the tube forms a closed cavity, and the heating and traction are continued. At the same time, the lifting and feeding device is slowly fed. By adjusting the pressure regulating gas source and the pressure regulating and relief valve to provide a pressure difference with the outside to adjust the ratio of the aperture and the outer diameter, a non-uniform ratio quartz glass tube is melted and drawn.
[0013] According to the above scheme, the aperture ratio (ratio of aperture to outer diameter) of the processed quartz glass tube increases with the increase of the pressure P of the adjustable pressure gas source, that is, the increase of the pressure difference between the closed cavity and the outside.
[0014] According to the above scheme, the air pressure buffer device is used to buffer the gas pressure change in the closed cavity caused by high temperature and melt stretching, wherein the cross-sectional area S1 of the U-shaped cavity sealing end of the air pressure buffer device is 0.01-0.2m 2 The cross-sectional area S0 of the opening end is 0.01~0.15m 2 The height H of the buffer interface arranged above one side of the sealing end of the U-shaped cavity is 0.25-0.35 m, and the buffer liquid in the U-shaped cavity is injected to a position where h0 is 0.10-0.20 m.
[0015] According to the above scheme, the pressure P of the adjustable pressure gas source is greater than the external gas pressure P0, and the liquid level height h1 at the sealing end of the U-shaped cavity is lower than the liquid level height h0 at the opening end of the cavity.
[0016] The beneficial effects of the present invention are as follows: 1. A sealing end cap is arranged at the upper end of the mother glass tube, and the sealing end cap is connected to an adjustable pure pressure gas source and an adjustable pressure relief valve, so as to provide a pressure difference higher than that of the outside to the inside of the mother glass tube, so as to control the aperture ratio of the processed quartz glass tube, and quartz glass tubes with different diameter ratios can be drawn, and the processing function and flexibility are greatly enhanced; 2. The pressure in the inner cavity of the tube is higher than the atmospheric pressure, which can prevent the pollution of the high-temperature zone tube by the impure gas outside; 3. The installation of the air pressure buffer device can effectively alleviate the gas pressure fluctuation in the closed cavity caused by high temperature and melt stretching, improve the uniformity of the aperture of the melt-drawn quartz glass tube, and thus improve the drawing accuracy of the non-uniform quartz glass tube; 4. The present invention has a simple and reasonable structure, is easy to use and control, and can meet the needs of actual use, especially the actual use of optical fiber preform rods. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a structural schematic diagram of an embodiment of the device of the present invention. DETAILED DESCRIPTION
[0018] The present invention is further described in detail below in conjunction with the accompanying drawings.
[0019] An embodiment of the device of the present invention is as follows Figure 1 As shown, a graphite furnace 7 is included for heating a mother glass tube 5. A clamping mechanism is correspondingly arranged above the graphite furnace, and the clamping mechanism is connected to a lifting and feeding device 6. A traction wheel 8 is correspondingly arranged below the graphite furnace, and a small sealing cover 9 is also arranged to be ... The air pressure buffer device comprises a U-shaped cavity, one end of the U-shaped cavity is sealed, the other end is open, and the lower end has a bottom cavity that communicates with both sides. The U-shaped cavity is filled with liquid higher than the bottom cavity, and a buffer interface is arranged above one side of the sealed end of the U-shaped cavity to communicate with the sealed end cover pipeline. The other end of the U-shaped cavity is open and communicates with the outside. The cross-sectional area S1 of the sealed end of the U-shaped cavity of the air pressure buffer device is 0.08m 2 , the cross-sectional area S0 of the opening end is 0.04m 2The height H of the buffer interface arranged above one side of the sealed end of the U-shaped cavity (relative to the liquid level of the bottom cavity) is 0.3m. The buffer liquid in the U-shaped cavity is injected to the position of 0.15m when the pressure P of the adjustable pressure gas source is equal to the external gas pressure P0. The adjustable pressure gas source pressure P is greater than the external gas pressure P0. The liquid level height h1 at the sealed end of the U-shaped cavity (relative to the liquid level of the bottom cavity) is lower than the liquid level height h0 at the opening end of the cavity, that is, h0 increases accordingly.
[0020] The fused drawing process of the quartz glass tube of the present invention is as follows: the upper end of the mother glass tube is clamped on the graphite furnace by the clamping mechanism by the above-mentioned drawing device, the lower part of the mother glass tube enters the furnace cavity of the graphite furnace, a sealing end cap is installed on the upper end surface of the mother glass tube, and the cavity of the mother glass tube is connected with the adjustable pressure gas source and the gas pressure buffer device through a pipeline, the mother glass tube entering the furnace cavity is heated by the graphite furnace, the heating temperature is above 1500°C, and the adjustable pressure gas source is opened at the same time, so that the mother glass tube is melted, thinned and extended downward, the glass tube assembly extending downward is cooled and hardened, and enters the traction wheel, and a small sealing cap is installed on the lower end of the processed quartz glass tube, so that the cavity inside the tube forms a closed cavity, heating and traction are continued, and the lifting and feeding device is slowly fed at the same time, and the ratio of the aperture to the outer diameter is adjusted by adjusting the adjustable pressure gas source to provide a pressure difference with the outside, so as to melt and draw a non-uniform quartz glass tube.
[0021] According to the above scheme, the pressure P in the closed cavity of the parent material is greater than the external gas pressure P0. The external atmospheric pressure is related to the local altitude. Here, the external atmospheric pressure P0 is 100000Pa, the internal cavity pressure is 101000Pa, and the liquid density in the U-shaped pressure stabilizing device is 1000kg / m 3 , the acceleration of gravity is 9.8N / kg, the liquid level h1 at the sealed end of the U-shaped cavity is lower than the liquid level h0 at the open end of the cavity, at this time, the height of h1 is 0.116m, and the height of h0 is 0.218m. The device of the present invention is used to draw a mother material with an outer diameter of 150mm and an inner hole of 50mm into a tube with an outer diameter of 35.5mm and an inner diameter of 31.5mm. The aperture ratio of the original mother material is 0.333, and the aperture ratio of the finished tube is 0.887, realizing non-proportional stretching. During the drawing process, the feeding speed of the mother material feeding mechanism is 1mm / min, and the traction wheel speed of the drawn tube is 74.6mm / min.
Claims
1. A drawing device for non-isotropic quartz glass tubes, comprising a graphite furnace, a clamping mechanism is arranged above the graphite furnace, the clamping mechanism is connected to a lifting and feeding device, and a traction wheel is arranged below the graphite furnace, characterized in that A sealing end cover is arranged on the upper end of the mother glass tube, and the sealing end cover is connected with an adjustable pressure gas source through a pipeline and is connected with a gas pressure buffer device.
2. The device for drawing a non-isotropic quartz glass tube according to claim 1, characterized in that A sealing device is provided which is configured with the lower end of the processed quartz glass tube.
3. The device for drawing a non-isotropic quartz glass tube according to claim 1 or 2, characterized in that The adjustable pressure gas source is a pure gas pressure source, and the pressure of the adjustable pressure gas source is higher than the atmospheric pressure.
4. The device for drawing a non-isotropic quartz glass tube according to claim 1 or 2, characterized in that The air pressure buffer device includes a U-shaped cavity, one end of the U-shaped cavity is sealed, the other end is open, and the lower end has a bottom cavity that communicates with both sides. The U-shaped cavity is filled with liquid that is higher than the bottom cavity, and a buffer interface is arranged above one side of the sealed end of the U-shaped cavity to communicate with the sealed end cover pipeline, and the other end of the U-shaped cavity is open to communicate with the outside world.
5. The device for drawing a non-isotropic quartz glass tube according to claim 4, characterized in that The height of the liquid in the U-shaped cavity is 1 / 3 to 2 / 3 of the height of the entire U-shaped cavity.
6. The device for drawing a non-isotropic quartz glass tube according to claim 1 or 2, characterized in that The pressure regulating gas source is connected to an adjustable pressure relief valve.
7. The device for drawing a non-isotropic quartz glass tube according to claim 1 or 2, characterized in that The adjustable pressure gas source is connected in series with a flow meter MFC and is also connected to a pressure gauge.
8. A method for drawing a non-isotropic quartz glass tube, characterized in that By using any device in claims 1-7, the upper end of the mother glass tube is clamped on the graphite furnace through a clamping mechanism, the lower part of the mother glass tube enters the graphite furnace cavity, a sealing end cap is installed on the upper end face of the mother glass tube, and the cavity of the mother glass tube is connected to the adjustable pressure gas source and the air pressure buffer device through a pipeline, the mother glass tube entering the furnace cavity is heated by the graphite furnace, the heating temperature is above 1500°C, and the adjustable pressure gas source is opened at the same time, so that the mother glass tube melts and becomes thinner and extends downward, the glass tube assembly extending downward cools and hardens, and enters the traction wheel, and a small sealing cover is installed on the lower end of the processed quartz glass tube, so that the cavity inside the tube forms a closed cavity, and heating and traction are continued. At the same time, the lifting and feeding device slowly feeds, and the ratio of the aperture to the outer diameter is adjusted by adjusting the adjustable pressure gas source to provide a pressure difference with the outside, so as to melt and draw a non-proportional quartz glass tube.
9. The method for drawing a non-isotropic quartz glass tube according to claim 8, characterized in that The aperture ratio of the processed quartz glass tube increases with the increase of the pressure P of the adjustable pressure gas source, that is, the increase of the pressure difference between the closed cavity and the outside.
10. The method for drawing a non-isotropic quartz glass tube according to claim 8, characterized in that The air pressure buffer device is used to buffer the gas pressure change in the closed cavity caused by high temperature and melt stretching, wherein the cross-sectional area S1 of the sealing end of the U-shaped cavity of the air pressure buffer device is 0.01-0.2m 2 The cross-sectional area S0 of the opening end is 0.01~0.15m 2 The height H of the buffer interface arranged above one side of the sealing end of the U-shaped cavity is 0.25-0.35 m, and the buffer liquid in the U-shaped cavity is injected to a position where h0 is 0.10-0.20 m.
11. The method for drawing a non-isotropic quartz glass tube according to claim 8, characterized in that The adjustable pressure gas source pressure P is greater than the external gas pressure P0, and the liquid level height h1 at the sealing end of the U-shaped cavity is lower than the liquid level height h0 at the opening end of the cavity.