A multi-scale modelling approach is proposed to better understand the behaviour of the freeze-drying of packed-bed of uniform and non-uniform particles. In particular, realistic geometric packing arrangements have been generated by using a bullet physics engine, while CFD simulation at the pore-scale has been used in order to obtain realistic values for the packed-bed; the results have then been used in a two-dimensional model describing heat and mass transfer in the freeze-drying of the packed-bed made of frozen particles.