Evaluation of Solar Regeneration of Silica Gel and its Use in Grain Drying
ABSTRACT SILICA gel was used to store solar energy for drying corn and milo. Three 75.4 kg lots of silica gel, 26 per-cent dry basis moisture content, were regenerated with solar energy for 2 days prior to and during the drying tests. A 1520 kg lot of corn, 23.5 percent wet basis moisture content and 0.66 m deep, was dried with a 40:60 mixture of ambient and desiccated air until the moisture content of the surface of the corn in the bin was below 15 percent wet basis; 280 hours were required. A duplicate lot (with a moisture content of 24.2 percent wet basis), was dried simultaneously with ambient air alone, required 350 hours. Mold counts and atlatoxin concentrations were significantly lower in corn dried with the mixture of am-bient and desiccated air. No significant difference in susceptibility to breakage attributable to drying method was found between the two lots. Two 1520 kg lots of milo, 18.5 percent wet basis moisture content and 0.53 m deep, were dried using the same airflow rate of 3.68 mVmin until the surface moisture content was below 16.2 percent wet basis. Dry-ing required 210 hours with 60:40 mixture of ambient and desiccated air and 330 hours with ambient air. Final average moisture contents were 12.6 and 14.4 percent wet basis, respectively.