MODELING AND SIMULATION OF CROSS-FLOW MOVING-BED GRAIN DRYERS

The drying of grain in dryers of a crossflow moving bed type was theor etically and experimentally studied. Two different dryer configuration s were analyzed, a dryer with central air distribution and another wit h multiple air ducts. Experimental information was obtained in pilot-s ize dryers. A mathematical model to simulate the process was developed . Hindered drying was accounted for by using the concept of relative d rying rate. An adjustable factor, specific to the dryers, was used to account for the uncertainties of the contact area and the transfer coe fficients encountered in the literature. Agreement between experimenta l results and simulations was fairly good. Simulations showed that dis tance between inlet air and outlet devices, air to solid flow ratio an d dryer height to cross section ratio have great influence on the proc ess. The mathematical model may be a useful tool for process explorati on and optimization of this type of dryers.