Heat Transfer in Chemical Vapor Deposited Optical Fiber Coatings

Mapping Intimacies ◽

10.1115/imece2001/htd-24371 ◽

2001 ◽

Author(s):

Patricia O. Iwanik ◽

Wilson K. S. Chiu

Keyword(s):

Heat Transfer ◽

Optical Fiber ◽

Gas Flow ◽

Convection Heat Transfer ◽

Fiber Surface ◽

Chemical Vapor ◽

Temperature Changes ◽

Flow And Heat Transfer ◽

Chemical Vapor Deposited ◽

Fiber Coatings

Abstract A fundamental understanding of how reactor parameters influence the fiber surface temperature is essential to manufacturing high quality optical fiber coatings by chemical vapor deposition (CVD). In an attempt to better understand this process, a finite volume model has been developed to study the gas flow and heat transfer of an optical fiber as it travels through a CVD reactor. This study showed that draw speed significantly affects fiber temperature inside the reactor, with temperature changes up to 45% observed under the conditions studied. Multiple heat transfer modes contribute to this phenomena, with convection heat transfer dominating the process.

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Heat and Mass Transfer in a CVD Optical Fiber Coating Process

Volume 3 ◽

10.1115/ht-fed2004-56320 ◽

2004 ◽

Author(s):

Wei Huang ◽

Wilson K. S. Chiu

Keyword(s):

Heat Transfer ◽

Optical Fiber ◽

Reaction Kinetics ◽

Gas Flow ◽

Chemical Vapor ◽

Parameter Study ◽

Inlet Temperature ◽

Transfer Model ◽

Phase Reaction ◽

Empirical Parameter

In this paper, we study the chemical vapor deposition (CVD) process used to hermetically coat optical fibers during draw. Temperature is calculated by coupling radiation and convection heat transfer by the reactor walls and gas flow with a radially-lumped heat transfer model for the moving optical fiber. Multi-component species diffusion is modeled using the Maxwell-Stefan equations. Gas-phase reaction kinetics is modeled using a 2-step chemical kinetics mechanism derived from RRKM theory with detailed kinetics data compiled from literature. Surface reaction kinetics are described using collision theory in which a sticking coefficient is used as an empirical parameter to predict surface reactions. A parameter study is carried out with various optical fiber inlet temperature and drawing speed, and validated with experiment results.

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Heat Transfer Correlations for a CVD Optical Fiber Coating Process

Heat Transfer, Volume 6 ◽

10.1115/imece2002-33919 ◽

2002 ◽

Author(s):

Patricia O. Iwanik ◽

Wilson K. S. Chiu

Keyword(s):

Heat Transfer ◽

Optical Fibers ◽

Gas Flow ◽

Temperature Drop ◽

Chemical Vapor ◽

Coating Process ◽

Numerical Heat Transfer ◽

Fiber Coating ◽

Flow And Heat Transfer ◽

Fiber Radius

A numerical heat transfer study of the chemical vapor deposition coating process used in the manufacture of optical fibers is conducted. A finite volume model, developed to study gas flow and heat transfer in the reactor and heat transfer within the fiber itself, is used. A parametric correlation relating percent temperature drop to the Peclet number and dimensionless fiber radius is determined. This correlation is expanded upon to obtain a correlation for the amount of energy loss as the fiber travels through the reactor. These equations are valid for fiber radius values ranging from 62.5 to 200 μm, and for draw rates ranging from 0.25 to 2.0 m/s.

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