Gas flow through a packed bed with low tube-to-particle diameter ratio: Effect of pellet roughness

Abstract

The packed beds are widely used in many industry sectors, such as energy, chemical engineering, and transportation. The prediction of fluid flow parameters is an important task for designing the packed bed units. In this study, the packed beds filled with spherical, cylindrical, and Raschig ring particles were experimentally and numerically investigated to understand the effect of pellet roughness on fluid flow parameters. The packed bed parameters were varied as follows: pellet roughness of 0.001–20 μm; velocity of 1–10 m/s; D/dp ratio of 2.9 and 4.8; packed bed length of 50–250 mm. It was established that the pressure drop increases significantly when the pellet roughness increases. Both numerical and experimental results showed a high deviation between our data and well-known empirical correlations. For this reason, a new correlation coefficient K for the Ergun equation taking into account pellet roughness was proposed. The correlation coefficient K provides a good correlation between the pressure drops calculated via the modified Ergun equation and the experimental/numerical data for a wide range of operational and design parameters.