Umudike Journal of Engineering and Technology

Michael Okpara University of Agriculture, Umudike


DEVELOPMENT AND PERFORMANCE EVALUATION OF A MEDIUM SCALE DIRECT MODE PASSIVE SOLAR DRYER FOR FARMERS IN NIGERIA

Eke, A. B.
Department of Agricultural and Bioresources Engineering, Michael Okpara University of Agriculture, Umudike, Umuahia, Abia State, Nigeria



ABSTRACT

Huge losses of vegetables due to inadequate processing systems are obvious among farmers in South-Eastern Nigeria. In order to abate this problem a medium scale direct mode passive solar dryer of capacity 50 kg of sliced okra was developed and evaluated at Michael Okpara University of Agriculture, Umudike between July and October 2014. A cabinet solar dryer housed with plastic corrugated transparent material was constructed for this study. Fresh okra sliced to a thickness of 15 mm was spread in single layer to dry in a solar dryer and in open sun as a control. Results obtained showed that the solar dryer raised the drying air temperature 31.82 oC to 45.54oC, which was 30.11 percent above the average ambient air temperature during the drying period. The ambient relative humidity was reduced from 73 % to 23.5 % in the solar dryer drying chamber where the sliced product was loaded. The moisture content of sliced okra reduced from 88% wet basis to 5% wet basis at 28 hours solar dryer effective drying time. The dryer achieved 40.1%  drying efficiency based on the effective drying time. Sliced okra samples dried in the solar dryer were of high qualities when compared with the sample dried in open sun.



Keywords: Solar, energy, passive, dryer, okra, plastic sheet


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Published
Wednesday, December 28, 2016

Issue
Vol. 2 No. 2, DEC 2016

Article Section
GENERAL

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