Análise da viabilidade técnica e validação de secador solar de baixo custo por meio da secagem de banana-passa

Abstract

Drying is one of the oldest known methods of food protection. The use of solar dryers to dehydrate fruits that presents injuries reduces waste and adds value to a product that would previously be discarded. In consideration of the above, the aim of this work was to validate two types of solar dryers, by obtaining dried banana and evaluating the internal temperature in the solar collectors. In order to evaluate the efficiency of the dryers in the drying process, air mass flow values were estimated considering an ideal system, to evaluate the values of drying air temperature and the modeling of the temperature as a function of the radiation. The physical and chemical characterization of the "in natura" banana and of the dehydrated samples by the two dryers were determined as well as the coefficient of shrinkage. Regarding the air mass flow estimation in the dryer, the values approximated those found in the literature. Analyzing the data, it was observed that both collectors were able to increase the temperature of the drying air, especially the collector with coverage, which reached greater amplitude and managed to maintain a higher temperature than the ambient air even with low solar radiation (end of the day). The characterization of the dried banana of the two dryers did not differ, however, the dryer with coverage provided faster drying of the samples and also obtained a lower coefficient of shrinkage. In observance of the results, both low-cost solar dryers were feasible in obtaining dried banana.