Soret, Dufour and Heat by Chemical Reaction Effects in a Chemical Vapor Deposition Optical Fiber Coating Process

2005 ◽  
Author(s):  
Wei Huang ◽  
Wilson K. S. Chiu
Keyword(s):  
Heat Transfer ◽  
Chemical Vapor Deposition ◽  
Optical Fiber ◽  
Chemical Reactions ◽  
Vapor Deposition ◽  
Soret Effect ◽  
Chemical Vapor ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Transfer Model

In this paper, we studied the effect of thermal diffusion (Soret effect), the heat flux due to species concentration gradient (Dufour effect) and the heat by chemical reactions in a chemical vapor deposition (CVD) process used to hermetically coat optical fibers. Using a previously developed mass and heat transfer model to investigate the transport phenomena in this process, the Soret and Dufour effects are compared to ordinary mass diffusion. The thermal conductivity, molecular diffusivity and thermal diffusivity are calculated using a multi-component model. The contribution of heat of chemical reactions to overall heat transfer in the CVD is also discussed. Soret effect and heat by chemical reactions are found to be very important in this process, and their effect is related to operating conditions such as draw speed and optical fiber inlet temperature.

Effect of Sub-Micron Thin Film on Surface Temperature During Chemical Vapor Deposition

2005 ◽  
Author(s):  
Wei Huang ◽  
Weixue Tian ◽  
Wilson K. S. Chiu
Keyword(s):  
Heat Transfer ◽  
Chemical Vapor Deposition ◽  
Optical Fiber ◽  
Vapor Deposition ◽  
Film Growth ◽  
Radiation Heat Transfer ◽  
Carbon Film ◽  
Chemical Vapor ◽  
Operating Conditions ◽  
Effective Emissivity

In this paper, we investigated the effect of the film thickness on heat transfer and subsequent film temperature distribution of an optical fiber as it traverses through a chemical vapor deposition (CVD) reactor. A 50 nm thick carbon coating is applied on the optical fiber as it moves through the CVD reactor. In this process, the only heat source is the hot optical fiber entering the CVD reactor from the draw furnace. Radiation heat transfer from the optical fiber as it is being coated plays an important role during CVD carbon film growth. The carbon film will change the effective emissivity of the optical fiber as it traverses through the CVD reactor. This study will calculate the effective emissivity of this film-fiber structure based on wave theory, and evaluate the optical fiber’s resulting temperature field and rate of heat transfer loss during chemical vapor deposition. Results are correlated to operating conditions.

Heat and Mass Transfer in a CVD Optical Fiber Coating Process

Volume 3 ◽  
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.

scholarly journals A Heat Transfer Model for Graphene Deposition on Ni and Cu Foils in a Roll-to-Roll Plasma Chemical Vapor Deposition System

2021 ◽  
Author(s):  
Majed Alrefae ◽  
Timothy S. Fisher
Keyword(s):  
Heat Transfer ◽  
Chemical Vapor Deposition ◽  
Temperature Distribution ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Plasma Chemical ◽  
Plasma Chemical Vapor Deposition ◽  
Roll To Roll

Abstract High-throughput production is a major bottleneck for integration of graphene-based technologies in existing and future applications. Here, a heat transfer model is developed to optimize large-scale deposition of graphene on Ni and Cu foils in a roll-to-roll plasma chemical vapor deposition (CVD) system. Temperature distributions in Ni and Cu foils during deposition are recorded with in situ temperature measurements using near-IR optical emission spectroscopy. The model indicates that foil movement significantly affects the temperature distribution and cooling rate of the foil. Consequently, graphene growth on Cu is limited to lower web speeds for which the foil temperature is higher and the residence time in the plasma is longer. On the other hand, graphene can be deposited on Ni at relatively higher web speeds due to moderately high diffusion rate of carbon in Ni and increased cooling rates with higher web speed. Critical limitations in the production rates of graphene using roll-to-roll CVD process exist due to significant effects of web speed on the temperature distribution of the substrate. The thermal analysis approach reported here is expected to aid in enhancing the throughput of graphene production in roll-to-roll CVD systems.

scholarly journals Jet Assisted Aerosol Chemical Vapor Deposition for Optical Fiber Synthesis

2002 ◽  
Vol 36 (3) ◽  
pp. 300-307 ◽  
Author(s):  
Mansoo Choi ◽  
Choonkeun Hong ◽  
Kong Hoon Lee
Keyword(s):  
Chemical Vapor Deposition ◽  
Optical Fiber ◽  
Vapor Deposition ◽  
Chemical Vapor

Optimization of Chemical Vapor Deposition Process

2006 ◽  
Author(s):  
Pradeep George ◽  
Hae Chang Gea ◽  
Yogesh Jaluria
Keyword(s):  
Thin Film ◽  
Chemical Vapor Deposition ◽  
Response Surface ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Transport Processes ◽  
Operating Conditions ◽  
Design Parameters ◽  
Large Area

Chemical Vapor Deposition (CVD) process is simulated and optimized for the deposition of a thin film of silicon from silane. The key focus is on the rate of deposition and on the quality of the thin film produced. The intended application dictates the level of quality need for the film. Proper control of the governing transport processes results in large area film thickness and composition uniformity. A vertical impinging CVD reactor is considered. The goal is to optimize the CVD system. The effect of important design parameters and operating conditions are studied using numerical simulations. Then Compromise Response Surface Method (CRSM) is used to model the process over a range of susceptor temperature and inlet velocity of the reaction gases. The resulting response surface is used to optimize the CVD system.

scholarly journals Synthesis of strong SiV photoluminescent diamond particles on silica optical fiber by chemical vapor deposition

2018 ◽  
Vol 27 (3) ◽  
pp. 038101 ◽  
Author(s):  
Zongchun Yang ◽  
Yingshuang Mei ◽  
Chengke Chen ◽  
Yinlan Ruan ◽  
Xiaojun Hu
Keyword(s):  
Chemical Vapor Deposition ◽  
Optical Fiber ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Diamond Particles ◽  
Silica Optical Fiber
Sign in / Sign up

Export Citation Format

Share Document