Resumo

CIRO VELASQUEZ, Héctor José; CORTES RODRIGUEZ, Misael  e  LOPEZ CASTANO, Jorge Luis. Intermittent Coffee Drying in Deep Bed with Pulsed Airflow. Rev. Fac. Nac. Agron. Medellín [online]. 2011, vol.64, n.2, pp.6247-6255. ISSN 0304-2847.

A dryer in deep bed without airflow reversal was adapted to work simultaneously with thermal intermittence and pulsed airflow in the drying of parchment coffee bean. The dryer was operated by cycles of thermal intermittence for a heating temperature of 55 °C and cooling of 40 and 25 °C. The results showed that the increase of temperature in the cycle of cooling tends to increase the water removal and that the increase of the number of air pulses without reversal of the direction of air flow causes an excessive moisture gradient within the batch. Moreover, the specific energy requirement of the dryer was from 15 to 25 MJ/kg, showing the best thermal performance for the condition in which the dryer was operate without pulsed airflow.

Palavras-chave : Parchment coffee; thermal efficiency; heat transference; biological material.

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