Journal of computational fluids engineering (한국전산유체공학회지)

Korean Society of Computational Fluids Engineering (한국전산유체공학회)
권호 표지

HELIUM CONCENTRATION DECREASE DUE TO AIR ENTRAINMENT INTO GLASS FIBER COOLING UNIT IN A HIGH SPEED OPTICAL FIBER DRAWING PROCESS

광섬유 고속인출공정용 유리섬유 냉각장치 내 공기유입에 의한 내부헬륨농도 저하현상 연구

  • 김경진 (금오공과대학교 기계공학부) ;
  • 김동주 (금오공과대학교 기계공학부) ;
  • 곽호상 (금오공과대학교 기계공학부) ;
  • 박상희 (금오공과대학교 기계공학부) ;
  • 송시호 (삼성광통신 광통신연구소)
  • Received : 2010.11.05
  • Accepted : 2010.12.17
  • Published : 2010.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

In a modern high speed drawing process of optical fibers, it is necessary to use helium as a cooling gas in a glass fiber cooling unit in order to sufficiently cool down the fast moving glass fiber freshly drawn from the heated silica preform in the furnace. Since the air is entrained unavoidably when the glass fiber passes through the cooling unit, the helium is needed to be injected constantly into the cooling unit. The present numerical study investigates and analyzes the air entrainment using an axisymmetric geometry of glass fiber cooling unit. The effects of helium injection rate and direction on the air entrainment rate are discussed in terms of helium purity of cooling gas inside the cooling unit. For a given rate of helium injection, it is found that there exists a certain drawing speed that results in sudden increase in the air entrainment rate, which leads to the decreasing helium purity and therefore the cooling performance of the glass fiber cooling unit. Also, the helium injection in aiding direction is found to be more advantageous than the injection in opposing direction.

Keywords

References

  1. 1996, Hiroshi, M., Handbook of Optical Fibers and Cables, Marcel Dekker, Inc., New York.
  2. 1999, Paek, U.C., "Free Drawing and Polymer Coating of Silica Glass Optical Fibers," Journal of Heat Transfer, Vol.121, No.4, pp.774-788. https://doi.org/10.1115/1.2826066
  3. 1979, Paek, U.C. and Schroeder, C.M., "Forced Convective Cooling of Optical Fibers in High-Speed Coating," Journal of Applied Physics, Vol.50, No.13, pp.6144-6148.
  4. 1981, Paek, U.C. and Schroeder, C.M., "High Speed Coating of Optical Fibers with UV Curable Materials at a Rate of Greater Than 5 m/sec," Applied Optics, Vol.20, No.23, pp.4028-4034. https://doi.org/10.1364/AO.20.004028
  5. 1986, Jochem, C.M.G. and Van der Ligt, J.W.C., "Cooling and Bubble-Free Coating of Optical Fibers at a High Drawing Rate," Journal of Lightwave Technology, Vol.LT-4, No.7, pp.739-742.
  6. 2000, National Research Council (U.S.), The Impact of Selling the Federal Helium Reserve, National Academy Press, Washington, D.C.
  7. 1993, Vaskopulos, T., Polymeropoulos, C. and Zebib, A., "Heat Transfer from Optical Fiber During the Draw Process," Journal of Materials Processing and Manufacturing Science, Vol.1, No.3, pp.261-271.
  8. 1995, Vaskopulos, T., Polymeropoulos, C. and Zebib, A., "Cooling of Optical Fiber in Aiding and Opposing Forced Gas Flow," International Journal of Heat and Mass Transfer, Vol.38, No.11, pp.1933-1944. https://doi.org/10.1016/0017-9310(94)00334-R
  9. 2001, Tschümperlé, D. and Nicolardot, M., "Fiber Cooling Modelisation During Draw Using CFD," Proceedings of ASME CFD Symposium: 3rd International Symposium on Computational Technologies for Fluid/Thermal/Chemical Systems with Industrial Applications, Atlanta, GA.
  10. 2001, Tschümperlé, D., Bourhis, J.F., Dubois, S. and Léon, A., "Study of Cooling Tubes for Fiber Drawing Using CFD," 50th IWCS Conference, Lake Buena Vista, FL.
  11. 2002, Tschümperlé, D. and Léon, A., "Design of an Efficient Cooling Tube for Optical Fiber Manufacturing at High Draw Speeds," 51th IWCS Conference, Lake Buena Vista, FL.