Comparative study of Performance of Open, Direct and Indirect Solar Dryer in Drying Tomatoes
Pages : 636-646
Solar drying system is essentially important for the preservation of agricultural crops for future use. In this work, the comparative study of performance of three different dryers was investigated. This was done by using the dryers in drying tomatoes crops. From the observation obtained, the daily maximum moisture content evaporated curves indicate decrease in the water contents of the drying material with number of days exposed to solar radiation. The trend of decrease is an exponential decay with the curves varying for the three dryers. The evaporated mass of the moisture content shows that the direct dryer perform higher than the indirect and open drying. The daily average moisture content evaporated graphs follow polynomial curves of degree 6 with coefficient of reliability of 90%. The direct dryer shows the highest daily average moisture content evaporated value follow by the indirect dryer then the open drying dryer. The hourly temperature variations for the three dryers are of polynomial curves of degree 6 with coefficient of reliability of 98 %. The daily maximum temperatures for the three dryers and the daily average temperatures for the three dryers show similar features and follow polynomial curves of degree 6 with coefficient of reliability of 85%. Generally for all the dryers, direct dryer shows the highest temperature variation, follow by indirect dryer then open drying dryer.
Keywords: Open Drying, Active dryer, Passive dryer (Direct Solar Cabinet and Indirect Solar Dryer).
Article published in International Journal of Current Engineering and Technology, Vol.3,No.2 (June- 2013)