title: Modeling moisture diffusivity, activation energy and specific energy consumption of squash seeds in a semi fluidized and fluidized bed drying.
abstract: This study investigated thin layer drying of squash seeds under semi fluidized and fluidized bed conditions with initial moisture content about 83.99% (d.b.). An experimental fluidized bed dryer was also used in this study. Air temperature levels of 50, 60, 70 and 80 °C were applied in drying samples. To estimate the drying kinetic of squash seed, seven mathematical models were used to fit the experimental data of thin layer drying. Among the applied models, Two-term model has the best performance to estimate the thin layer drying behavior of the squash seeds. Fick's second law in diffusion was used to determine the effective moisture diffusivity of squash seeds. The range of calculated values of effective moisture diffusivity for drying experiments were between 0.160 × 10(-9) and 0.551 × 10(-10) m(2)/s. Moisture diffusivity values decreased as the input air temperature decreased. Activation energy values were found to be between 31.94 and 34.49 kJ/mol for 50 °C to 80 °C, respectively. The specific energy consumption for squash seeds was calculated at the boundary of 0.783 × 10(6) and 2.303 × 10(6) kJ/kg. Increasing in drying air temperature in different bed conditions led to decrease in specific energy value. Results showed that applying the semi fluidized bed condition is more effective for convective drying of squash seeds. The aforesaid drying characteristics are useful to select the best operational point of fluidized bed dryer and to precise design of system.
authors.affiliation: Department of Agricultural Machinery Engineering, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran.
authors.forename: Reza Amiri
authors.initials: RA
authors.lastname: Chayjan
authors.affiliation: Department of Agricultural Machinery Engineering, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran.
authors.forename: Kamran
authors.initials: K
authors.lastname: Salari
authors.affiliation: Department of Agricultural Machinery Engineering, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran.
authors.forename: Qasem
authors.initials: Q
authors.lastname: Abedi
authors.affiliation: Department of Irrigation and Drainage Engineering, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran.
authors.forename: Ali Akbar
authors.initials: AA
authors.lastname: Sabziparvar
keywords: Fluidized bed drying; Moisture diffusivity; Squash seeds; Thin layer drying