DRYING FIGS USING DEVELOPMENT MECHANICAL DRYER

Abstract

The present work was conducted to study and simulate the drying behavior of whole figs fruits under different drying parameters. The approach led to develop a small scale industrial figs dryer using butane-gas as heat energy source and also describe the change in whole figs moisture content during actual drying process using the proposed dryer. The experimental were carried out using fresh whole figs “Ficus Carica” its local name is Sultani. Whole figs fruits were treated before drying by treatment (A): the fruits sulfured by dipped in 1.5% aqueous sodium metabisulfit and, treatment (B): the fruits were dipped in 1% sodium hydroxide before treated with solution of 1.5% sodium metabisulfit. Four levels of drying air temperature (55, 65, 75 and 85 °C) and four levels drying air velocity (0.2, 0.4, 0.6 and 1 m/s) The results showed that, the reduction rate of whole figs moisture content was increased with the increasing of drying air temperature and air velocity in all pretreatment of simple whole figs. On the other hand, the whole figs moisture content reduction rates on the treatment (B) were higher than that in treatment (A) for all the combination of the parameters. The recorded drying time for drying whole figs from an initial moisture content of about 223-400% d.b to a final moisture content of about 18-20% d.b were 35-20hours under different drying parameters. Heating control unit using butane-gas was used to control heat source in drying air temperature with fluctuation of about ±1.7 °C for all levels of drying air temperature. The total capacity of the dryer is about 40 kg of fresh figs producing about 10 kg of dried figs, the calculated operation cost of the dryer approaches about 6.3 LE/kg of dried whole figs fruits. The developed dryer of whole figs fruits showed good mechanical and thermal performance.