Experimental Investigation of Two-Pass Solar Dryer with V-Corrugated Absorber for Potato Slice Drying

Reducing the moisture level of food items can help prevent bacterial development and deterioration, extend shelf life, reduce packaging, and improve storage for convenient transportation. In this paper, a two-pass solar dryer with V-Corrugated absorber plate is developed. Its experimental performance evaluation in forced convection is carried out for potato chip drying. Various parameters like Hourly Variation of Solar Radiation Intensity, Temperature Distribution Curves inside Solar Dryer, Collector Efficiency Curve, Hourly Mass Loss of Potato Slices and Moisture Removal Comparison with Conventional Open Sun Drying Method are calculated and presented graphically. The peak temperature of the absorber plate reached 69.30C, and the air temperature at the collector outlet recorded the highest value at 57.50C. The average temperature difference of 28.580C is obtained for heat transfer by convection between the modified corrugated absorber plate and the air. An important finding in this experimental investigation was that there is an average 6.50C difference in temperature between the hot air exiting the collector and the air available at the bottom of the lower tray of the drying chamber, which should be reduced by applying means of avoiding heat loss. The highest collector efficiency is calculated as 88.9 % at 2 PM. The lowest efficiency is calculated at 9 AM as 66.8 %. The thermal inertia of the system adds to the collector efficiency in the last 2 hours of the experimentation and hence collector performs better than in the morning hours, though the insolation is nearly the same for the first and last two hours of sunshine. The percentage reduction in drying time was found to be 38.9 % for 50 % moisture removal from potato slices as compared to open sun drying.