Performance analysis of a dryer design for drying cinnamon chips

Abstract

Drying is one of the most important pre-processing techniques in cinnamon oil industry. Sun drying is the conventional method of drying cinnamon chips but has some inherent disadvantages of long processing times, dependency on climatic conditions, labor cost and most importantly, the deterioration of quality due to several factors; dust, fungus, insects, etc. A tray dryer was designed to mitigate the drawbacks of conventional drying and to reduce the post harvesting losses by optimizing the drying operation. The dryer which was operated by convective drying using heated air consisted of 3 main units; stove, heat exchange and drying chamber. Drying temperature was selected as the varying parameter while the other operational parameters such as pressure, humidity and velocity of air were kept constant. The drying time could be reduced from 14 hours to 4 hours by increasing the temperature from room temperature to 50 °C but the oil yield started to drop in drying above 35 °C. The drying rate of samples kept at different tray locations within the dryer was found to be significantly different. Since uneven drying affected the oil yield, a method for achieving uniform drying was suggested using the drying curve data to achieve higher oil yield.