Characterization of Single and Multi Sizes Sphere Packing

 This work presents the study of fluid flow through a packed bed, where two fluids were used separately (air and water). The packed bed contains spherical glass particles distributed randomly.The packed bed was 7.62 cm in diameter and 57 cm long. The glass particles were 0.42, 0.50, 0.61, 0.79 and 1.01 cm in diameter. Different flow rates of fluid were used which expressed by modified Reynolds number. The experiments were carried out at laboratory temperatures (32 ◦C) for air flow and at tap water temperature (25 ◦C) for water flow. Many variables were studied in this work such as fluid type (air or water), flow rate and the packing porosity (mono, binary, and multi-size mixture), in order to study the effect of these variables on the pressure drop and friction factor.The results showed that the pressure drop through a packed bed is highly sensitive to the packing porosity which has a significant effect on the friction factor. It was found that as the bed porosity increases from 0.3455 to 0.4359 the friction factor values decrease from 0.808  to 0.366, and the pressure drop values decrease from 33.8 to 7.1 Pa The air flow Reynolds number was ranged from 8.42 to 265.63 which lead to decrease in the friction factor values from 0.992 to 0.374. For water flow the Reynolds number range from 38.47 to 1504.22 which lead to decrease in the friction factor values from 0.456 to 0.284.It was studied the effect of working fluid (air and water) on the pressure drop and friction factor through the packed bed. It was found that for the same packing porosity and fluid flow rate the pressure drop of air flow was less than the pressure drop of water flow.  Empirical correlations for friction factor as a function of Reynolds number for air and water flow through packed of multisizes particles are: