Development and performance evaluation of an okra drying machine
Research Journal of Applied Sciences, Engineering and Technology
Department of Agricultural Engineering, Ile-Ife, Nigeria; Department of Mechanical Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria
An okra dryer was designed, constructed and evaluated in this study for post-harvest processing of the fruit. The dryer consists of a heating chamber, two drying trays, a blower of 1 hp, two heating elements of 2000W each, 4 roller tyres for ease of mobility, a control box which consist of a thermostat that regulates the temperature in the dryer. The result of evaluation of the dryer in no load indicated that it was able to yield temperature very close to the preset (by the thermostat) after about 3 min. The dryer was evaluated by drying okra of different thickness (5 and 10 mm), in two trays at two heights (25cm and 50cm from the bottom) and at a preset temperatures of 50 and 70°C. Moisture losses from the slices were obtained at intervals of 30, 45, 60 and 90 min. The result showed that increase in temperature from 50 to 70°C, increases moisture loss from the slices. Slices of 5 mm thickness were observed to dry faster than 10 mm slices with those on the upper tray losing more moisture. The study further showed that slice thickness of 5 mm dried at 70°C in the upper tray level of 60 cm from the base of the dryer are suitable for drying okra slices in the dryer. © Maxwell Scientific Organization, 2011.
Development; Evaluation; Okra dryer; Postharvest; Slices; Driers (materials); Dryers (equipment); Moisture; Thermostats; Drying