Open AccessDEVELOPMENT OF DIRECT MODE NATURAL CONVECTION SOLAR DRYER FOR HIGH MOISTURE CONTENT CROPS
Author(s) -
A B Eke
Publication year - 2017
Publication title -
american journal of agricultural science, engineering, and technology
Language(s) - English
Resource type - Journals
eISSN - 2164-0920
pISSN - 2158-8104
DOI - 10.54536/ajaset.v1i1.13
Subject(s) - solar dryer , water content , relative humidity , environmental science , moisture , solar energy , horticulture , pulp and paper industry , materials science , meteorology , composite material , engineering , biology , geography , geotechnical engineering , electrical engineering
Farmers find it extremely difficult and in most cases impossible to process and preserve high moisture content crops by normal open sun drying. In order to ameliorate this identifiedproblem, five direct mode natural convection flat plate high moisture content solar dryers weredesigned and constructed with locally available materials. Sliced fresh ripened Ronita Cultivartomato and mango as well as fresh okra, carrot and onion were used to test run the solar dryers.While the samples of the same crops dried in open sun were used as control. The tests wereconducted in the months of January, February, March and April, 2005 and the average ambientvalues 31.4 oC, 16.11 %, 1.32 m/s and 570.9 W/m2 for temperature, relative humidity, windspeed and solar energy radiation respectively, were used in the analysis. Evaluation of dryingsystems’ performances indicated that over 50 percent savings in drying time was achieved withthe solar dryers as compared to the open sun drying. Also the system drying efficiencies of thedryers revealed that tomato, onion, okra, mango and carrot dried in solar dryers attained 105.85,66 60, 64.25, 100.00 and 93.97 percent respectively higher than the system drying efficiencies ofthe same samples dried in open sun. Each of the dryers generated an average daily drying airtemperature of over 49oC and less than 55oC.