Analysis of transport phenomena in the coating of fibers by CVD

Authors

J H. Scholtz, Laboratory for ceramic and reaction engineering, Department of chemical engineering, State University of New York at Buffalo, New York, 14260.
J E. Gatica, Laboratory for ceramic and Reaction Engineering, Department of chemical Engineering, State University of New York at Buffalo, New York.
Hendrik J. Viljoen, University of Nebraska-LincolnFollow

Date of this Version

9-1-1991

Comments

This article was published in Journal De Physique IV, Colloque C2, Suppl. au Journal De Physique II, Vol 1, Septembre 1991, C2-135 - C2-142. Original version of this article is available at the publishers site www.edpsciences.org/jp4

Abstract

Inorganic coated fibres produced by chemical vapour deposition find several technological applications. In this CVD process, a filler core is mounted in a reactor between two electrodes. Reactive gases flow over the substrate and react near or on the fibre surface to form the desired coating. Experience has showed that, quality deposition can only be obtained over a small range of the governing parameters: these parameters are, however, difficult to control. In the present, study a mathematical model is developed for the reactor configuration under consideration. The different mass and energy transport mechanisms are compared and their influence on the react or performance is evaluated for horizontal reactor arrangements. Numerical results, showing sharp temperature and concentration gradient close to the fibre surface suggest that heat and mass transfer in this region are controlled by conduction and diffusion mechanisms. In the bulk region, heat and mass transfer via the convection and conduction diffusion mechanisms can be of equal importance. Numerical results show how bulk properties are affected by both transversal and longitudinal rolls.