TY - JOUR
T1 - Linear and Nonlinear Drying Behavior in Tuberous Crop Slices
AU - Sandoval Torres, Sadoth
AU - Allier González, Adriana L.
N1 - Publisher Copyright:
© 2015, Taylor & Francis Group, LLC.
PY - 2015/4/4
Y1 - 2015/4/4
N2 - Understanding drying physics is a complex task because interactions between phases and variations in thermal properties change over time. In this investigation we used two models to simulate the drying of potatoes slices. Drying kinetics were modeled by both the drying characteristic curve (DCC) method and by a mechanistic approach implemented in COMSOL Multiphysics. The DCC was developed on the basis of experimental data and a referential drying rate, which for potatoes is the maximum evaporation rate during the process. The surface thermal evolution was considered to estimate the drying rate curve and the drying stages. The phenomenological model considers both the transport of free water and water vapor by applying a mechanistic approach. In order to simulate free water transport we took into account the capillary diffusivity term, and to simulate water vapor evacuation we considered the desorption isotherm. Two drying conditions were analyzed, 1.0 and 2.2 m/s of air flow with 60°C and 30% relative humidity (RH). The mechanistic model solves the primary unknown's moisture content, temperature, and dry air density. Both models were compared against experimental data. The simulation correctly describes the drying kinetics for the trial at 2.2 m/s and fails to simulate the phenomena at 1.0 m/s. Two different drying behaviors influenced by air flow speed were identified by following the evolution of surface temperature and mass flux. The dependence of mass flux on the difference in temperature (Tair−Tsurface) shows that the area of exchange is a very important parameter to be considered in simulations, because both linear and nonlinear behaviors are manifested.
AB - Understanding drying physics is a complex task because interactions between phases and variations in thermal properties change over time. In this investigation we used two models to simulate the drying of potatoes slices. Drying kinetics were modeled by both the drying characteristic curve (DCC) method and by a mechanistic approach implemented in COMSOL Multiphysics. The DCC was developed on the basis of experimental data and a referential drying rate, which for potatoes is the maximum evaporation rate during the process. The surface thermal evolution was considered to estimate the drying rate curve and the drying stages. The phenomenological model considers both the transport of free water and water vapor by applying a mechanistic approach. In order to simulate free water transport we took into account the capillary diffusivity term, and to simulate water vapor evacuation we considered the desorption isotherm. Two drying conditions were analyzed, 1.0 and 2.2 m/s of air flow with 60°C and 30% relative humidity (RH). The mechanistic model solves the primary unknown's moisture content, temperature, and dry air density. Both models were compared against experimental data. The simulation correctly describes the drying kinetics for the trial at 2.2 m/s and fails to simulate the phenomena at 1.0 m/s. Two different drying behaviors influenced by air flow speed were identified by following the evolution of surface temperature and mass flux. The dependence of mass flux on the difference in temperature (Tair−Tsurface) shows that the area of exchange is a very important parameter to be considered in simulations, because both linear and nonlinear behaviors are manifested.
KW - Drying characteristic curve
KW - Exchange area
KW - Mass flux
KW - Physics-based model
KW - Thermal driving force
UR - http://www.scopus.com/inward/record.url?scp=84924204786&partnerID=8YFLogxK
U2 - 10.1080/07373937.2014.955919
DO - 10.1080/07373937.2014.955919
M3 - Artículo
SN - 0737-3937
VL - 33
SP - 559
EP - 569
JO - Drying Technology
JF - Drying Technology
IS - 5
ER -