DUALPURPOSE SOLAR OVEN

Dual purpose solar oven (DPSO) was designed and constructed. It observed that by using the new design of solar oven, both function of cooking and drying were possible for meeting the requirement of a family. The maximum stagnation temperature of 119°C and water temperature of 93.25°C were obtained in winter in DPSO while using as cooker. The calculated values of figure of merit F in DPSO was 0.119 and the time duration 1 for raising water temperature from 60 C to 90°C in hot box was 120 min. Cooking trials have also been conducted 0.5 kg of rice in 1 kg of water and 0.250 Kg of green gram split washed in one and half hrs in winter while it took about one hour in summer. The maximum temperature of 58 °C was recorded at 14:00 hrs of the day at level of tray no.2 when used as dryer. The time required to dry maize on different trays upto average moisture content 7.13 %( w.w.) for winter and 5.43 %( w.w.) for summer (w.w.)was 420 minute and 360 minute respectively. The total cost of solar oven was worked out to be Rs().2,715. Its pay back period varied between 1.3 to 1.86 years depending upon fuel it replaced.