Three-dimensional convection caused by a slightly tilted crucible and a small deviation from a constant temperature gradient furnace during the vertical Bridgman growth is analysed using a novel three-dimensional finite-volume code (STHAMAS 3D). The obtained results show that three-dimensional flow is induced by these deviations from a perfect axisymmetry. It is also shown that these effects are stronger for the semi-transparent materials than for the opaque ones.