Modeling the thin-layer drying process of Granny Smith apples: Application in an indirect solar dryer

Open sun drying experiments in thin layers of crain-crain (CC), fever (FV) and bitter (BT) leaves grown in Abeokuta, Nigeria were conducted. The drying process took place in the falling rate period and no constant rate period was observed from the drying curves. Eight thin layer mathematical drying models were compared using the multiple determination coefficients (R2), reduced chi-square (χ2) and root mean square error (RMSE) between the observed and predicted moisture ratios. Accordingly, Midilli et al. model satisfactorily described the drying curves of the three leaves with R2 of 0.9980, χ2 of 2.0×10-4 and RMSE of 1.09×10-2 for CC leaves; R2 of 0.9999, χ2 of 2×10-6 and RMSE of 1.11×10-3 for FV leaves; and R2 of 0.9998, χ2 of 1.9×10-5 and RMSE of 3.3×10-3 for BT leaves. The effective diffusivity was found to be 52.91×10-10, 48.72×10-10 and 43.42×10-10 m2/s for CC, BT and FV leaves, respectively.

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Mathematical modelling of the thin layer drying of pineapple (Ananas comosus, L.): experiment at village-scale in a greenhouse type solar dryer

Ingeniería Investigación y Tecnología ◽

10.22201/fi.25940732e.2019.20n2.016 ◽

2019 ◽

Vol 20 (2) ◽

pp. 1-10

Author(s):

Ignacio López Cerino ◽

Irineo Lorenzo López Cruz ◽

Serm Janjai ◽

Marcus Nagle ◽

Busarakorn Mahayothee ◽

...

Keyword(s):

Experimental Data ◽

Moisture Content ◽

Thin Layer ◽

Large Scale ◽

Linear Regression Analysis ◽

Ananas Comosus ◽

Solar Dryer ◽

Thin Layer Drying ◽

Best Fitting ◽

Drying Curves

The objectives of this research were two: first to investigate experimentally the behavior of pineappl (Ananas comosus, L.) thin layer drying in a greenhouse-type solar dryer and second to describe the best fitting kinetic and mathematical model taken from literature. A large scale greenhouse dryer designed and installed at Silpakorn University, Nakhon Pathom, Thailand was used to dry slices 1 cm width at temperature range between 25-60 °C with relative humidity between 50-90%. Nine statistical models, either empirical or semi-empirical, were tested in order to validate the experimental data. A non-linear regression analysis conducted by a statistical computer program was applied to evaluate the constants of all the models. The parameter values, root mean square error (RMSE), mean absolute error (MAE) and modelling efficiency (EFF) of the nine models were calculated. Comparison outcomes of two experiments are displayed between the predicted moisture content and the observed pineapple moisture content. Hasibuan and Daud drying model proved to describe the best pineapple solar drying curves. The two experiments were carried out on sunny days, the second experiment on the third day showed cloudiness decreasing the solar radiation. Mathematical models of pineapple drying in a greenhouse dryer have not been found so far in the literature. Drying curves obtained from experiments showed that the constant drying and the falling drying rate periods exist. Nine thin-layer drying models were fitted to two experimental data in order to describe the drying characteristics of pineapple founding that the Hasibuan and Daud model was the best fitting.

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Modeling the thin Layer Drying Kinetics of Cocoa Beans in a Passive Solar Dryer and under Open Sun

10.13031/aim.201900244 ◽

2019 ◽

Author(s):

Ifeanyi Wilfred Okonkwo ◽

Tobechukwu E. Okorie

Keyword(s):

Thin Layer ◽

Drying Kinetics ◽

Cocoa Beans ◽

Solar Dryer ◽

Thin Layer Drying ◽

Passive Solar ◽

Kinetics Of

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Drying Process Modelling for Heavy Clay Products Using a New Thin Layer Drying Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.371.323 ◽

2013 ◽

Vol 371 ◽

pp. 323-327

Author(s):

Miloš Vasić ◽

Zagorka Radojević

Keyword(s):

Thin Layer ◽

Mathematical Models ◽

Process Modelling ◽

Experimental Investigations ◽

Drying Process ◽

Thin Layer Drying ◽

Heavy Clay ◽

Drying Models ◽

Drying Model ◽

Thin Layer Drying Models

Drying results, determined on samples made of masonry clay from the locality "Banatski Karlovac", are presented in this study. Experimental investigations were carried out in a laboratory recirculation dryer in which drying parameters (humidity, temperature, and velocity) could be programmed, controlled and monitored during drying process. Several mathematical models were used for drying process modelling. New semi-theoretical thin layer drying model, for heavy clay products, was developed and presented in this study. It represents a modification of Page's and logarithm's thin layer drying models. Results presented in this study have shown that new thin layer drying model describes and correlates the best experimentally determined drying process.

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