New applications of expanded perlite in the building industry lead to a growing demand for process optimization for the expansion of perlite. Perlite expanders aim to adapt their furnaces and/or furnace operation conditions in order to attain more flexibility to produce different expanded perlite qualities. A way to examine the possibilities of an existing installation is the numerical simulation of the perlite expansion process in that installation. The two-phase flow field and combustion in the furnace can be modelled by using currently available Computational Fluid Dynamics (CFD) codes. The only problem is the modelling of the expansion process, which changes the particle size and thus influences the two-phase flow calculations. In this paper the authors propose a physical model for the simulation of the expansion of perlite.
