Experimental study of innovative indirect solar dryers

Abstract

The present work experimentally studied two novel solar dryers' designs, novel indirect solar dryer (NISD) and novel mixed indirect solar dryer (NMISD). The purpose behind this work is to compare the thermal performance of the proposed dryers with that of a traditional indirect solar dryer (TISD). The testing method involved building and thermally testing the three dryers. The NISD is a novel drying chamber with three absorbed surfaces. The NMISD consisted of a flat plate solar collector and NISD. The air temperature at the drying chamber entrance increased by 60% and 68% for the TISD and NMISD, respectively. In the lower space of the drying chamber, the air temperature was decreased by 35% while increased by 39% for the NISD and NMISD, respectively, compared to the TISD. The air temperature in the upper space of the drying chamber increased by 14% and 49% for the NISD and NMISD, respectively, compared to the TISD. The temperature variations through the drying chamber were -26%, 33%, and 3% in the TISD, NISD, and NMISD, respectively. The thermal efficiencies of the NISD and NMISD were 9% and 55%, respectively, higher than the TISD's.