To determine the energy saving potential available from recirculating air in peanut drying, a thin layer drying simulation model was adapted to incorporate recirculation. A heat and mass balance computer model was developed to enable the determination of heat energy input. Laboratory crop dryers were designed and constructed to conduct experiments to verify the simulation models. Five batches of peanuts were dried using different recirculation strategies and the model successfully predicted the experimental results, including moisture content and wet and dry bulb temperatures. Energy savings of up to 20 percent were realized in the experimental runs. The simulation model was also used to evaluate and compare several recirculation strategies in order to determine successful strategies. / Master of Science

Virginia type peanuts were dried in three laboratory dryers to verify a simulation model based on Troeger and Butler's drying equations. The energy saving potential of air recirculation was also investigated. Four tests consisting of eleven drying experiments were conducted in Fall, 1986. Two air recirculation schedules were employed and three average air flow rates were used. An experimental procedure was developed to measure input and output parameters of the drying system. The weight loss of the top layer of the peanut bed was recorded with a data acquisition system. The electrical energy input to the heaters was also recorded. Based on the analysis of the data, the following conclusions were made: (1) The Troeger model predicted a lower moisture release rate than the actual rate for Virginia type peanuts. (2) If the break points in the Troeger model were changed to 0.20 and 0.70 from 0.12 and 0.40, respectively, the model predicted the final moisture content more accurately. (3) Energy savings as high as 50 percent were achieved using the recirculation schedules. / Master of Science

This study indicates that peanuts can be dried continuously using supplemental heat and still retain a palatable flavor. It has brought to focus many problems heretofore recognized. / Master of Science