Spatial variation of moisture content along the axial distance of corn at different superheated steam drying temperatures and various instantaneous times

Abstract

Superheated steam acts as both a heat source and a drying medium. The study sought to predict the evolution of the moisture transport behaviour of the corn kernel at various axial distances at varying instantaneous time. The equations describing the drying phases were solved using numerical solutions with the Eulerian technique in ANSYS software. Cone geometry was used to simulate the corn kernel with initial moisture content at 20% w.b. Steam conditions were similar to what is encountered in industry, with temperatures ranging (from 120–200°C) at 1.5 m s−1 velocity. ANOVA was used to determine if there was difference between the conditions. The temporal change in moisture from the apex to the periphery varied at superheated steam temperatures 120, 160 and 200°C. At 10, 100 and 200 s the drying rate and effective moisture diffusivity of corn kernel from the centre towards the periphery differed. Post‐hoc analysis with Bonferroni adjustment revealed that moisture content (w.b.%) differed between 10 and 100 s, 10 and 200 s and 100 and 200 s. The mean difference was attributed to the drying being in the falling drying phase at 200 s and initial condensation at 10 s. Thus, at high superheated steam temperatures, dry zones can be seen as the axial distance from the apex increases toward the periphery.