The rotating cone reactor is a novel reactor type which can be used for rapid thermal solids processing. This paper focuses on particle dynamics and gas-phase hydrodynamics in a rotating cone reactor as a first stage to obtain a basic understanding of the processes that govern the performance of this reactor. Therefore, the flow of nearly spherical monosized PVC powder in a cold-flow rotating cone reactor has been studied under variation of the particle diameter (140-780 mum), the cone rotational speed (up to 1800 rpm) and two different cone top-angles (60 and 90-degrees). The gas flow created by the rotating cone showed a marked influence on motion of particles smaller than 200 mum. A mathematical model is presented using a single-particle description, and a turbulent ps flow description near the wall according to the universal velocity profile. The experimentally observed residence time of the particles inside the present reactor is typically in the order of 0.2 s.