The present work deals with the study of the thermal performances of a
convective dryer for fruits and vegetables. This dryer, operating with energy
generated from the combustion of biomass in a
boiler connected to a water/air heat exchanger could be a solution to the
problematic of energy related todrying.
An experimental and theoretical study is carried out on the temperature
profile inside the dryer. For this purpose, 10.3 kg of tomatoes were
dried on the experimental setup. The operation lasted about 16 hours and
reduced the moisture content from 93.8% to
12% in wet basis. The overall thermal efficiency of the convective dryer during
the trial is 10.76%. For the theoretical study, the dryer components (boiler, water/air exchanger and drying chamber) are first modeled individually; the different sub-programs are then
coupled to form the convective dryer program. The method of global heat
balances combined with the one called “ε-NUT” is
used. The set of equations is discretized using
the implicit method of finite differences, then solved with the Gauss algorithm
in Fortran 90. The theoretical results obtained are in good agreement
with those measured.
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