Abstract: Liquids containing solid materials in soluble or suspended form are atomized in a chamber while admitting a drying gas. Partially dried particles settle to the bottom of the chamber and are collected on a perforated conveyor belt where they are subject to a final drying in order to obtain a homogeneous porous layer while drawing drying gas through the layer. The generation of a whirling movement in the lower part of the chamber immediately over the part of the conveyor belt where the particles settle ensures an even distribution of the particles while forming a layer of a constant thickness on the conveyor belt.