Influence of floor air entry on grain moisture content, temperature, and bulk shrinkage during ambient air in-bin drying of wheat

Wheat at 22% m.c. (w.b.) was dried using ambient air in an experimental bin with a fully perforated, a partially perforated, or a slanted perforated f loor. When grain was dried in the bin with a partially perforated floor, mo isture contents of the grain were distributed in such a way that higher moi sture content grain was at the sides of the bin. When grain was dried in th e bin with a slanted perforated floor, grain at the center of the bin remai ned wet throughout the drying process. Profiles of inter-granular temperatu re contours were similar to profiles of moisture content contours. Higher t emperatures corresponded to lower moisture contents. Inter-granular air tem perature remained at or near the wet-bulb temperature of the drying air unt il the grain moisture content decreased to 15% (w.b.). A curved grain surfa ce resulted from uneven bulk grain shrinkage due to non-uniform airflow. At the same plenum static pressure and with the same volume of grain, air ent ering the bin with a partially perforated floor was about 78% of that with a fully perforated floor. K