DESIGN, CONSTRUCTION AND EVALUATION OF A SMALL SCALE SOLAR DRYER
1Onigbogi I.O, Sobowale, S. Sand Ezekoma, O.S
Department of Food Technology
Moshood Abiola polytechnic Abeokuta, Ogun State
E-mail: sunsam_2003@yahoo.co.uk
ABSTRACT
The solar drying system utilizes solar energy to heat up air and to dry any food substance loaded, which is beneficial in reducing wastage of agricultural product and helps in preservation of agricultural product. Based on the limitations of the natural sun drying e.g. exposure to direct sunlight, liability to pests and rodents lack of proper monitoring, and the escalated cost of the mechanical dryer, a solar is therefore developed to cater for this limitation. This project presents the design and construction of a domestic passive solar dryer.The dryer is composed of solar collector (air heater) and a solar drying chamber constraining rack of three cloth (net) trays both being integrated together. The air allowed in through air inlet is heated up in the solar collector and channeled through the drying chamber where it is utilized in drying. The design was based on the geographical location which is Abeokuta and meteorological data were obtained for proper design specification. The dimensions of the dryer is 94cm x 45cm x 101cm / 20cm (length x width x height). Locally available material were used for the construction, chiefly comprising of wood (gmelina), glass, aluminum metal sheet, copper and net cloth for the trays. The optimum temperature of the dryer is 50.50OC with a corresponding ambient temperature of 34.50o C. The moisture content removal of 43.2% and 40.6% in maize and plantain respectively using the solar dryer was achieved as against 28.2% and 27.89% in maize and plantain using the sun drying method and indication 15.0% and 12.71% difference respectively, the rapid rate of drying in the dryer reveals its ability to dry food items reasonable rapidly to a safe moisture.
Keywords: Solar dryer, Moisture loss, Design and Construction, Maize and Plantain