DRYING STUDY OF EUCALYTPTUS STAIGERIANA LEAVES BY MONITORING THE HUMIDITY OF THE DRYER DISCHARGE

Abstract

The drying phenomenon can be treated as simultaneous heat and mass transfer in both the
light and heavy phases. In the present case, the phenomenons evolution is normally
observed through the heating of and moisture removal from the heavy phase. On the other
hand, while the material is heating, the light phase is cooling and humidifying. The goal
of the present work is to present discharge air humidification curves as a function of the
drying time for Eucalyptus staigeriana leaves drying experiments. For the air humidification
measurements, a dry bulb thermocouple and relative humidity transducer were installed
at both the dryer inlet and outlet. The dryer was linked to a data acquisition system, which
recorded the dry bulb temperature and the relative humidity with time. These data were
later used to calculate the air moisture content at the dryer inlet and outlet. The data obtained
by this methodology are compared with the ones from drying kinetic (moisture content
removing of the heavy phase along time), acquired by the evolution of wet material weight
through the use of an analytical scale.