Modeling heat and mass transfer in the heat treatment step of yerba maté processing

Brazilian Journal of Chemical Engineering

J. M. Peralta¹  M. E. Schmalko¹ 

[1] ,National University of Misiones College of Exact, Chemical and Life Sciences Posadas Misiones ,Argentina

关键词: Yerba maté;    Heat treatment;    Modeling;    Heat transfer;    Mass transfer;   

DOI  :  10.1590/S0104-66322007000100007

来源: SciELO

【 摘 要 】

The aim of this research was to estimate the leaf and twig temperature and moisture content of yerba maté 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 135°C and then it slowly decreased to 88°C at the exit, despite the gas temperature, which varied in this zone from 460°C to 120°C. Twig temperature increased in the two zones from its inlet temperature (25°C) up to 75°C. A model error of about 3% was estimated based on theoretical and experimental data on leaf moisture content.

【 授权许可】

CC BY   
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