Comparison of Drying Kinetics of Maize in Oven and in Pilot Silo Dryer: Influence on Moisture Content and Physical Characteristics

摘要

The study of process kinetics may aid the design and optimization of drying systems. This paper evaluated the influence of drying temperature (40, 60 and 80 °C) on the moisture content, drying rate, density, shrinkage and breakage of maize dried in two different dryers: oven and silo dryer. In both dryers, the temperature increase reduced drying time, final moisture content and shrinkage of the grains, however increased breakage. Drying rate was higher in the oven (6.4 × 10~(?4) ± 2.3 × 10~(?4)s~(?1) versus 5.4 × 10~(?4) ± 1.2 × 10~(?4)s~(?1)), while shrinkage (15.2 ± 4.7% versus 24.4 ± 5.6 %) and density increase (16.6 ± 5.9% versus 33.4 ± 5.8%) were more intense in the silo. There was a large release of husk in the silo dryer and the moisture content was slightly smaller in the lower layers respective to the upper ones.