Vol. 11, Issue 12 (2022)

Author(s):
Rohit Kumar Yadav and Dr. Sheen C Moses

Abstract:
Solar drying is becoming a popular option to replace mechanical dryers due to the high cost of energy, and the increased awareness of consumer orientation to clean energy products. In this study, three different low-cost solar dryers, viz. solar tunnel dryer (STD), cabinet solar dryer (CSD), and open sun drying (OSD) were examined, and green peppers drying experiments were carried out on each. In this study, three main topics were determined: (i) to compare the drying rate of each solar drying method (ii) to determine the drying time of each solar drying systems, (iii) to compare the drying efficiency of each solar dryer. For these purposes, 3 experiments were conducted between 10:00am–04:00pm at the department of renewable energy engineering campus in shuats, Prayagraj (u.p.). The average daily solar irradiance was around 890 W/m2. In drying experiments, it was observed that the samples were completely dried out within the experiment period, while the drying process of the green pepper in STD were completed in 14 hr and in CSD and OSD were completed after 28 hrs. The results show that the drying time of STD is less than CSD and OSD. Drying rate and drying efficiency of STD is more than CSD and OSD. Mint leaves have a thermal efficiency of 40.04% in the winter and 44.68% in the summer when dried in a sun tunnel. Slices of potatoes used in a solar tunnel dryer have a thermal efficiency of 78.14% in the winter and 93% in the summer. The thermal efficiency of green chilies for solar tunnel dryers in the winter and summer, respectively, is 49.34% and 82.94%. For the cabinet type solar dryer, mint leaves have a thermal efficiency of 34.46% in the winter and 40.38% in the summer. For cabinet-style solar dryers, the thermal efficiency of potato slices is 74.44% in the winter and 84.45% in the summer. Last but not least, the thermal efficiency of green chilies for a cabinet type solar dryer is 43.38% and 69.31% in the winter and summer, respectively. Mint leaves may be dried in a solar tunnel dryer with an efficiency of 21.84% in the winter and 34.14% in the summer. In the winter and the summer, the solar tunnel dryer's effectiveness for drying potato slices is 44.99% and 49.69%, respectively. Last but not least, the solar tunnel dryer's drying efficiency for green chilies in the winter and summer, respectively, is 36.72% and 42.29%. Mint plants can be dried with an efficiency of 20.92% in the winter and 32.60% in the summer using the cabinet type solar drier. Potato slices may be dried using cabinet-style solar dryers with an efficiency of 43.55% in the summer and 39.47% in the winter. Last but not least, a cabinet-style solar drier can dry green chilies with an efficiency of 30.11% or 37.39% depending on the season.