Investigation of a simulation model for peanut drying incorporating air recirculation

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.