Design of Solar Dryer Assisted with Reflector for Drying of Medicinal Crops

Preservation of fruits, vegetables, and food are essential for keeping them for a long time without further deterioration in the quality of the product. Solar drying has been used since time immemorial to dry plants, seeds, fruits, meat, fish, wood, and other agricultural, forest products. The aim of the dryer is mainly for the welfare of the marginalized and poor farmers those who can’t afford hi-tech facilities and equipment’s to preserve their agricultural products. Drying of Safed Musli (Chlorophypum boribilianum) in open sun drying require more time and affected its quality. In order to maintain quality and to increase sufficient temperature in the drying chamber during winter, morning and evening hours, a solar dryer assisted with reflector was designed. The main principle of this domestic solar dryer is based on greenhouse effect where the solar heat is trapped inside the drying chamber and thus increases the temperature in addition to reflected direct radiations. A domestic dryer assisted with reflector was designed and developed for drying of safed musli in batch. The dryer was fabricated as per design specification and its performance was evaluated in the Department of Unconventional Energy Sources and Electrical Engineering, Dr. PDKV, Akola. The paper deals with design, material and experimental techniques used for studying the performance evaluation of a domestic solar dryer assisted with reflector for drying of safed musli. At no load test without reflector the maximum temperature of 51.24°C was achieved in the afternoon and average temperature in the solar dryer was found to be 41.02°C at corresponding ambient temperature of 21.7°C, solar radiation 430.86 W/m2, relative humidity 23.26%, in the morning of December 2014. The maximum temperature recorded in December 2014 was 58.46 at 13.30 h. The average temperature of domestic dryer was found to be 44.22°C at ambient temperature of 31.3°C, relative humidity 31.7%, solar radiation 553.80 W/m2 during the month of March 2015.The average moisture content of Safed Musli samples placed in T1, T2 and T3 trays reduced from 651.5 to 4.5, 654.7 to 7.7 and 656 to 14.5 % (db) in 8 h, respectively in domestic solar dyer integrated with reflector. The average moisture content of Safed Muslisample reduced from 613 to 7.8 % (db) in 12 h. Average drying rate was found to be 0.5526, 0.54103 and 0.53455 gm/100gm bdm min, respectively. The average drying efficiency of Safed Musli samples dried in domestic solar dryer with reflector was found to be 22.92 % respectively.