Abstract

In this work, a solar drying system was constructed, consisting of three parts (solar collector, drying chamber, and air blower). Solar collector having V-corrugated absorption plate of two air passes, a single glass cover was used. The total area of the collectors is 2.04 m². The dimension of the drying chamber is 1.06, 0.66 and 0.56 m for width, depth, and height, respectively. 38 kg of corn were dried. The moisture content was reduced from 21 to 13% within four hours drying. The drying air temperatures at the inlet of the dryer were found in the range of 30 to 45°C when the range of ambient air temperature was from 8.5 to 20°C and total solar radiation intensity was from 270 to 560 W/m². Increasing volumetric air flow rate from 0.025 to 0.030 m³/s raises the daily solar collector efficiency by 3.25%, while increasing volumetric air flow rate from 0.030 to 0.035 m³/s raises the solar daily collector efficiency by 11.11%. The drying rate is reduced with the decrease of moisture content. Efficiency of the collector is very much dependant on air flow rate.

Key words: Solar energy, solar air collector, two passes collector, V-corrugated collector, solar drying, performance evaluation.