Desidratação de polpa de umbu em leito de jorro: estudos fluidodinâmicos e térmicos.

Abstract

The use and industrialization of tropical fruits constitutes a viable alternative for the development of the Northeast. The umbuzeiro (Spondias Tuberosa Arruda), tree native to this region, very resistant to drought, produces tasty fruits, rich in vitamin C and other nutrients equally valuable. In this work, we studied the drying of the umbu pulp in spouted bed, a simple technology that provides good quality products at low cost. How s and treats relatively new technique, the existing data in the literature with respect to heat transfer and fluid dynamics of the bed, with pastes and suspensions, are quite scarce. A series of dehydration, the results of which allowed an assessment of thermal and fluid dynamic characteristics of the process. It was found that the presence of the suspension alters the dynamic characteristics, increasing pressure drop reducing the minimum spout flow and the circulation of solids, among others. With regard to thermal behavior, studied the effect of operational variables on the efficiency, finding that e s t decreases with air flow and with the temperature. From the heat exchange coefficients, it was possible to evaluate the fraction of wet particles and correlate it with the pulp flow / volume particles. The proposed thermal model proved to be consistent with the experimental data. It was also observed that the dehydration of the umbu pulp in a spouted bed is found limited by fluid dynamic conditions, especially by feeding system.