The article presents the concept of a high-temperature solar dryer with an internal bed storage. Granite was selected as the material for filling the bed storage, and an emphasis was put on its versatile use and favourable thermal and mechanical properties. Experimental tests were carried out for the charging process of the bed storage, which was filled with granite spheres with three different diameters. The influence of the sphere's diameter on the charging and discharging process of the bed storage was analysed. The results of the experiment allowed a conclusion to be drawn that the use of a granite storage bed could prolong the operation of the considered dryer by two hours.
Keywords: granite spheres; heat storage; solar dryer.