Moisture Diffusivity and Activation Energy Estimation of White Yam (Dioscorea rotundata) Slices Using Drying Data from a Refractance WindowTM Dryer
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Date
2019
Authors
Akinola, A. A.
Ezeorah, S. N.
Journal Title
Journal ISSN
Volume Title
Publisher
FUOYE Journal of Engineering and Technology
Abstract
The objective of this study was to estimate the moisture diffusivity of different sizes of white yam slices at different temperatures using a Refractance WindowTM dryer. To achieve this objective, dehydration of 1.5, 3.0 and 4.5 mm thick yam slices was performed with water temperatures of 65, 75, 85 and 95 oC in the flume of a Refractance WindowTM dryer. Variation of moisture content with dehydration time data were obtained during the dehydration operations. The activation energies of dehydration for different sizes of yam slices were estimated for the temperatures considered. For the process conditions studied, the effective moisture diffusivities varied from 5.35 x 10-08 to 1.45 x 10-07 m2/s. The effective moisture diffusivity, Deff, at a specified temperature was observed to increase with increasing yam slice size. The effective moisture diffusivity, Deff, at a specified yam slice size is observed to increase with increasing dehydrating temperature. The activation energy, Ea, for the yam slices, ranged from 23.21 to 28.30 (kJ/mol) and it was observed to increase with increasing thickness of the yam slices. The activation energy values estimated were within the range observed for other equipment. This study is important in that, the moisture diffusivities and activation energy parameters estimated will be useful in the design, modelling, and optimization of such dryers.
Description
Staff publications
Keywords
Yams , Moisture diffusivity , Activation energy , Refractance window TM , Dryer , Research Subject Categories::TECHNOLOGY::Chemical engineering
Citation
Akinola, A. A. and Ezeorah, S. N., (2019). Moisture Diffusivity and Activation Energy Estimation of White Yam (Dioscorea rotundata) Slices Using Drying Data from a Refractance WindowTM Dryer. FUOYE Journal of Engineering and Technology, Vol 4(1), pp 102 – 106.