Evaluation of air flow resistance across a green fig bed for selecting an appropriate pressure drop prediction equation

Abstract

In this study the physical properties of green fig ( Ficus carica L.) at different moisture contents were measured. Pressure drop across a bed of green fig was also evaluated. The moisture content and air flow ranges used in this study were 5.74–34.08% (db) and 0.2–1.1 (m 3 s −1 m −2), respectively. To measure resistance to air flow an appropriate test rig was designed and fabricated. A thick bed of seven depths of loose and random filling of fig bed were envisaged (5, 10, …, 35 cm). Principle dimensions, geometric mean diameter, sphericity, roughness factor of fig kernels and bulk density increased with an increase in moisture content, whereas kernel density and porosity decreased with an increase in fig moisture content. The air flow resistance across the bed increased with an increase in bed depth and moisture content. The modified Ergun model with higher values for coefficient of determination, lower values for root mean square error and mean relative deviation modulus was the best model for predicting pressure drop across green figs bed for the conditions studied.