Journal of Emerging Trends in Engineering and Applied Sciences: Research Areas

Abstract:
A gas-fired crop dryer was developed in this work. The dryer consisted of dryer cabinet with four drying trays, a fan, heating chamber with Liquefied Natural Gas (LNG) burner, and control unit which houses the thermostat. The performance of the dryer was evaluated using two different slice thicknesses of 5 and 10mm; and two different air flow velocities of 5 and 7.5 m/s, at a constant drying temperature of 500C.Results obtained from the evaluation showed that the dryer dried okra slices from an average initial moisture content of 80.1% (wet basis) to an average final moisture content of 23.68% (wet basis) in a time of 90 minutes. The research also revealed that the drying rate of okra slices increased with decreasing values of slice thickness and increasing values of air flow velocities. The fastest drying rate of 48.01%/hr was obtained for the 5 mm sized slices dried at 7.5 m/s; while the slowest drying rate of 26.56%/hr was obtained for the 10 mm sized slices dried at 5 m/s.the drying efficiency of the dryer increased with increasing air flow velocities and decreasing slice thickness of okra. The drying efficiencies of the dryer ranged from 68.91% to 80.96%. The performance of the dryer showed that it could be used effectively in drying of okra slices and other crops.

Keywords: Liquefied Natural Gas, Slice Thickness, Air Flow Velocity, Drying Rate, Drying Efficiency

Download full paper