Experimental investigation of fluid flow and heat transfer in a randomly packed bed of sinter particles

• Fluid flow and heat transfer performance of RPBSP is experimentally investigated.
• Naphthalene sublimation technique is used to study heat transfer characteristics.
• Heat transfer coefficients of RPBSP are larger than these with spheres.
• New heat transfer correlations are obtained for RPBSP.

Fluid flow and heat transfer in a randomly packed bed of sinter particles (RPBSP) is experimentally investigated. Based on the Chilton–Colburn analogy, heat transfer performance is obtained by the naphthalene sublimation technique. The sinter particles, which are coated with naphthalene, are sublimated to obtain the mass transfer characteristics. The results of pressure drop (Δp) in the RPBSP show that most experimental values are within the ±20% deviations of the modified Ergun’s equation. The results of Nusselt number (Nu) indicate that, the heat transfer characteristics of the randomly packed bed of the irregular particles are different from that of regular surface particles. Slopes of heat transfer correlations of the RPBSP are larger than these with spheres. Based on the experimental investigations, we employ genetic algorithm (GA) to derive heat transfer correlations. It is found that the GA approach can correlate Nu quite well and two new correlations are obtained to describe convective heat transfer in the RPBSP. Comparisons between correlations developed in the present work and other correlations are also conducted. Lastly, effects of sphericity and porosity are included in a heat transfer correlation when considering physics and heat transfer characteristics. The investigation provides thoughts for dealing with the packed beds with irregular particles, as well as the newly obtained correlations for construction of the mathematical model in sinter cooling bed and design of new cooling equipment.