DRYING BEHAVIOR OF PEANUTS USING A ROTARY DRYER

Abstract

A study was carried out to test and evaluate high-temperature short-time drying behavior of peanuts pods using a laboratory scale rotary dryer. The experimental work was conducted at six different levels of cylinder surface temperature 55, 65, 75, 85, 95 and 105 o C, three levels of cylinder rotational speed 3, 6 and 9 (r.p.m) and three peanut batch masses 1, 1.5 and 2 (kg/batch). The high temperature rotary drier was evaluated in terms of operating factors likewise moisture regiem, drying temperature, pods and kernels temperatures, batch mass feed, cylinder rotational speed and compatibility of experimental data to Lewis models. The optimal treatment of the high temperatur dried pods of peanuts was slected in terms of physical characteristics of microbiological quality parameters, percentages of broken, splitted, shriveled kernels, oil content of peanuts, free fatty acids and peroxide value of peanuts oil. The results show that, heating surface temperature of 65 o C, cylinder rotational speed of 6 r.p.m and pods batch mass of 1.5 kg recorded the lowest values of kernels splitting, broken and shriveling percentages. The mathematical analysis showed that, Lewis model could satisfactorily describe the drying behavior of high moisture peanuts pods.