We present a transient model for the Modified Lely. Method for the sublimat
ion growth of SiC single crystals which consists of all conservation laws i
ncluding reaction-diffusion equations. The model is based on a mixture theo
ry for the gas phase. First numerical results illustrate the influence of t
he geometrical set-up inside the reactor on the evolution of the temperatur
e distribution. (C) 1999 Elsevier Science B.V. All rights reserved.