MARIA POPA, ION ONUTU FLUID-DYNAMICS CHARACTERISTICS CONCERNING THE FIXED BED USAGE OF RING PARTICLES
The paper shows a study on the fluid-dynamics characteristics of the fixed bed of ring particles, associated with certain characteristics of the heat transfer in such systems. Water was used as working fluid circulating through a fixed bed of ring particles. The fluid circulates with low velocity, making possible a certain pressure drop, given by the friction of the fluid with the surface of the solid particles, by the trajectories imposed to each electricity wave by the presence of the particles and turbulence resulted from the flow over obstacles. For this study were chosen two types of ceramic ring particles. They are characterized by defined ratio Hp / De = 10.3 / 9.2 mm and 5.4 / 4 mm. The friction factor was calculated from experimental data with Fanning’s relation and the value obtained was compared with the theoretical value obtained from Ergun’s relation.
Keywords: ring particles, pressure drop, exchanger with coaxial tubes, fluid-dynamics characteristics