Comparison of Theoretical and Experimental Corn Drying Profiles Within a Cross-Flow Column Dryer

Abstract

This study compared the drying characteristics of corn within a continuous flow dryer under a variety of operating conditions. The tests were completed on a pilot scale cross flow corn dryer with variable fan speed and column thickness. The dryer column has a height of 3.35 m (132 in.), width of 0.61 m (24 in.) and variable thicknesses ranging from 0.30–0.36 m (12–14 in.). In addition, the drying air temperature and air flow rate per volume of grain were varied. An array of thermocouples measured the thermal profile of the corn bed within the dryer. The dryer exhaust was divided into four zones, each 0.83 m (33 in.) tall. Each zone measured incoming air velocity and exhaust temperature and relative humidity. Using these measured values in conjunction with the known ambient conditions, the theoretical amount of moisture removed from each zone was calculated. Corn dryer efficiency and throughput are becoming increasingly important, as it is the second largest cost associated with corn production. Improved farming practices, in conjunction with improved corn genetics, have resulted in increased yields and the ability to grow corn in locations not possible two decades prior. The overarching goal of this research is to help determine the key factors which help to dry corn more efficiently.