Design and Performance Evaluation of a Multi Functinal Passive Solar Dryer for Paddy

Abstract

A multi functional passive solar yer was designed and constructed by adding the solar water heater and the solar air heater. The yer consists of solar collector, reflector, riser tube cum heat storage unit and ying chamber. The storage tank of the conventional solar water collector is modified as riser tubes and header, which is fitted in the bottom of the solar air heater as an absorber in the normal air hea ter. The ying chamber was loca ted under the collector. The system is worked as a solar yer only, by preventing the flow of water, during the sun-shine (without water heating) in a sunny day, the ying system efficiency was found 21. 44% whereas, it found 35. 83% when adding heat energy from the water heater with a low intensity of solar radiation during the sun-shine and the ying process by the multi fun ctional solar yer only. The solar yer was tested for ying of paddy. The capacity of the yer was to y about 5-10 kg of paddy in 8 h in sunny day from an initial moisture content of 76. 4% to the final moisture content of 9. 4% (wb). For a ying time about 8 h, the moisture content of the paddy using the solar yer was 0. 16 kg/kg (db) and for the ied paddies by the sun dying was