%0 Journal Article
%T Modeling heat and mass transfer in the heat treatment step of yerba mat¨¦ processing
%A Peralta
%A J. M.
%A Schmalko
%A M. E.
%J Brazilian Journal of Chemical Engineering
%D 2007
%I Brazilian Society of Chemical Engineering
%R 10.1590/S0104-66322007000100007
%X the aim of this research was to estimate the leaf and twig temperature and moisture content of yerba mat¨¦ branches (ilex paraguariensis saint hilaire) during heat treatment, carried out in a rotary kiln dryer. these variables had to be estimated (modeling the heat and mass transfer) due to the difficulty of experimental measurement in the dryer. for modeling, the equipment was divided into two zones: the flame or heat treatment zone and the drying zone. the model developed fit well with the experimental data when water loss took place only in leaves. in the first zone, leaf temperature increased until it reached 135ˇăc and then it slowly decreased to 88ˇăc at the exit, despite the gas temperature, which varied in this zone from 460ˇăc to 120ˇăc. twig temperature increased in the two zones from its inlet temperature (25ˇăc) up to 75ˇăc. a model error of about 3% was estimated based on theoretical and experimental data on leaf moisture content.
%K yerba mat¨¦
%K heat treatment
%K modeling
%K heat transfer
%K mass transfer.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0104-66322007000100007&lng=en&nrm=iso&tlng=en