scholarly journals Modeling of convective drying kinetics of Pistachio kernels in a fixed bed drying system

2013 ◽  
Vol 17 (3) ◽  
pp. 839-846 ◽  
Author(s):  
Asım Balbay ◽  
Ömer Şahin ◽  
Hakan Ülker
Keyword(s):  
Initial Moisture Content ◽  
Fixed Bed ◽  
Effective Diffusivity ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Air Temperatures ◽  
Drying Behavior ◽  
Drying System ◽  
Drying Conditions ◽  
Kinetics Of

Drying kinetics of Pistachio kernels (PKs) with initial moisture content of 32.4% (w.b) was investigated as a function of drying conditions in a fixed bed drying system. The drying experiments were carried out at different temperatures of drying air (40, 60 and 80?C) and air velocities (0.05, 0.075 and 0.1 m/s). Several experiments were performed in terms of mass of PKs (15g and 30g) using a constant air velocity of 0.075 m/s. The fit quality of models was evaluated using the determination coefficient (R2), sum square error (SSE) and root mean square error (RMSE). Among the selected models, the Midilli et al model was found to be the best models for describing the drying behavior of PKs. The activation energies were calculated as 29.2 kJ/mol and effective diffusivity values were calculated between 1.38 and 4.94x10-10 m2/s depending on air temperatures.

scholarly journals Drying behavior, diffusion modeling of cuminum cyminum L. undergoing microwave-assisted fluidized bed drying

2018 ◽  
Author(s):  
Gholamreza Askari ◽  
Atefe Babaki ◽  
Zahra Emamdjomeh
Keyword(s):  
Fluidized Bed ◽  
Effective Diffusivity ◽  
Air Velocity ◽  
Cuminum Cyminum ◽  
Fluidized Bed Dryer ◽  
Microwave Assisted ◽  
Air Temperatures ◽  
Drying Behavior ◽  
Fluidized Bed Drying ◽  
Kinetics Of

In order to conserve cuminum cyminum L. during long storage periods, the drying kinetics of this seed undergoing microwave-assisted fluidized bed dryer at various microwave output power (300, 600 and 900w), air velocity (10, 15 and 20 m/s) and air temperatures (45, 55 and 65ᵒc) were studied. The main aim of this research is developing a mathematical model of mass transfer to investigate the microwave-assisted fluidized bed drying of cuminum cyminum L. seed. In this paper, we tried to discover a good model to evaluate moisture effective diffusivity (Deff). Keywords: cuminum cyminum L, microwave-assisted drying, mathematical modeling,

scholarly journals Mathematical modeling of pequi pulp drying and effective diffusivity determination

2017 ◽  
Vol 21 (7) ◽  
pp. 493-498 ◽  
Author(s):  
Elisabete P. de Sousa ◽  
Rossana M. F. de Figueirêdo ◽  
Josivanda P. Gomes ◽  
Alexandre J. de M. Queiroz ◽  
Deise S. de Castro ◽  
...  
Keyword(s):  
Experimental Data ◽  
Effective Diffusivity ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Drying Time ◽  
Air Speed ◽  
Drying Curves ◽  
Increasing Temperature ◽  
Kinetics Of ◽  
Best Fit

ABSTRACT The aim of this work was to study the drying kinetics of pequi pulp by convective drying at different conditions of temperature (50, 60, 70 and 80 °C) and thickness (0.5, 1.0 and 1.5 cm) at the air speed of 1.0 m s-1, with no addition of adjuvant. The experimental data of pequi pulp drying kinetics were used to plot drying curves and fitted to the models: Midilli, Page, Henderson & Pabis and Newton. Effective diffusivity was calculated using the Fick’s diffusion model for a flat plate. It was found that, with increasing thickness, the drying time increased and, with increasing temperature, the drying time was reduced. The Midilli model showed the best fit to the experimental data of pequi pulp drying at all temperatures and thicknesses, presenting higher coefficients of determination (R2), indicating that this model satisfactorily represents the pequi pulp drying phenomenon. There was a trend of increase in the effective diffusivity with the increase in pulp layer thickness and temperature.

scholarly journals Influence of the temperature and ultrasound application in drying kinetics of apple skin

2018 ◽  
Author(s):  
Juan A. Cárcel ◽  
Matheus P. Martins ◽  
Edgar J. Cortés ◽  
Carmen Rosselló ◽  
Ramón Peña
Keyword(s):  
Physical Structure ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Drying Time ◽  
Different Temperatures ◽  
Ultrasound Application ◽  
Quality Of Products ◽  
Drying Conditions ◽  
Kinetics Of ◽  
By Products

The great amount of waste produced by food industry contains interesting bioactive compounds. The extraction of these compounds requires the by-products previous stabilization being the convective drying one of most used techniques to this end. Drying conditions can affect both drying kinetics and final quality of products. The apple skin, byproduct of apple juice or cider industries, is rich in functional compounds such as polyphenols or vitamin C. The main goal of this contribution was to quantify the influence of temperature and ultrasound application in drying kinetics of apple skin. For this purpose, drying experiments at different temperatures (-10, 30, 50 and 70 ºC) and with (20.5 kW/m3) and without application of ultrasound were carried out. Drying kinetics were modelled by using a diffusion based model. As can be expected, the higher the temperature the faster the drying. Ultrasound application accelerated the process at every temperature tested being the influence slightly lower than found from the literature for other products. This can be attributed at the physical structure of the apple skin, less porous than the pulp. In any case, the application of ultrasound significantly reduced the drying time. Keywords: by-products; dehydration;diffusivity; mass transfer

Air Drying Kinetics of Pomegranate Seeds

2011 ◽  
Vol 7 (2) ◽  
Author(s):  
Sajeev Rattan Sharma ◽  
Sadhna Arora ◽  
Tarsem Chand
Keyword(s):  
Activation Energy ◽  
Moisture Content ◽  
Effective Diffusivity ◽  
Air Drying ◽  
Air Temperatures ◽  
Thin Layer Drying ◽  
Activation Energy For Diffusion ◽  
Drying Behavior ◽  
Pomegranate Seeds ◽  
Kinetics Of

The thin layer drying of pretreated wild pomegranate seeds was conducted in a laboratory mechanical dryer at air temperatures of 55, 60 and 65°C. Six different mathematical models were used to predict the drying behavior. Thompson model was adjudged as the best model. The coefficients of this model were found to be correlated best with drying temperatures by using two degree polynomials. The effective diffusivity was determined to be 3.18 x 10-10 to 4.36 x 10-10 m2/s. The activation energy for diffusion was found to be 29.07 kJ /mol. The variation in shrinkage exhibited a linear relationship with moisture content. The rate constants for “a” and “b” parameters of colour were determined and their value was 0.0128 and 0.0136 min-1, respectively.

An Experimental Study on the Drying Kinetics of Castor Bean Fruits (Ricinus communis L., “Brs Energia” Variety)

2016 ◽  
Vol 369 ◽  
pp. 119-124
Author(s):  
E.M.A. Pereira ◽  
J.V. Silva ◽  
J.P.S. Santos ◽  
T.H.F. Andrade ◽  
A.G. Barbosa de Lima
Keyword(s):  
Experimental Study ◽  
Castor Bean ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Effective Moisture Diffusivity ◽  
Effective Moisture ◽  
Air Temperatures ◽  
Thin Layer Drying ◽  
Drying Behavior ◽  
Kinetics Of

This work aims to conduct an experimental study of the drying kinetics of castor bean fruits (Ricinuscommunis L., “BRS Energia” variety). Experiments were conducted using an oven at air temperatures 50 and 70°C and air relative humidity values 16.34 and 6.24%, respectively. The castor bean fruits were considered as a triaxial spheroid. The experimental moisture content data as a function of time were fitted to different lumped models (namely Henderson and Pabis, Page, Midilli and two-term exponential models) available in the literature.The values of the effective moisture diffusivity were obtained from the Fick's diffusion model. Results shows that the two-term drying model could adequately describe the thin layer drying behavior of castor bean fruit, and that the effective moisture diffusivity increases with increasing drying air temperature.

scholarly journals  Modeling some drying characteristics of garlic sheets under semi fluidized and fluidized bed conditions

2012 ◽  
Vol 58 (No. 2) ◽  
pp. 73-82 ◽  
Author(s):  
R. Amiri Chayjan ◽  
K. Salari ◽  
B. Shadidi
Keyword(s):  
Thin Layer ◽  
Fluidized Bed ◽  
Air Temperature ◽  
Specific Energy Consumption ◽  
Initial Moisture Content ◽  
Convective Drying ◽  
Air Temperatures ◽  
Thin Layer Drying ◽  
Drying Behavior ◽  
Drying Properties

Thin layer drying properties of high moisture garlic sheets under semi fluidized and fluidized bed conditions with high initial moisture content (about 154.26% d.b.) were studied. Air temperatures of 50, 60, 70 and 80&deg;C were applied to garlic samples. Among the applied models, Page model was the best to predict the thin layer drying behavior of garlic sheets. Using this model, correlation coefficient (R<sup>2</sup>) was high for all drying cases. The computed values of D<sub>eff</sub> were between 3.38 &times; 10<sup>&ndash;10</sup> and 2.54 &times; 10<sup>&ndash;9</sup> m<sup>2</sup>/s during the falling rate drying. Values of D<sub>eff</sub> for garlic sheets were also increased with increasing in input air temperature. Activation energy values were varied between 51.32 and 60.58 kJ/mol for 50 to 80&deg;C, respectively. The specific energy consumption (SEC) for garlic specimens was placed in the range of 0.316 &times; 10<sup>6</sup> and 0.979 &times; 10<sup>6</sup> kJ/kg from 50 to 80&deg;C, respectively. An increase in air temperature caused decrease in SEC value. Application of semi fluidized bed convective drying with temperature between 50 and 60&deg;C was suitable to produce dried garlic. &nbsp; &nbsp;

scholarly journals THE EFFECT OF MICROWAVE OUTPUT POWER ON DRYING KINETICS OF YOGHURT AND MATHEMATICAL MODELING OF DRYING CURVES

2021 ◽  
Vol 51 (2) ◽  
pp. 127-131
Author(s):  
Ayşe Nur Yüksel
Keyword(s):  
Effective Diffusivity ◽  
Microwave Oven ◽  
Drying Kinetics ◽  
Layer Model ◽  
Domestic Microwave Oven ◽  
Drying Behavior ◽  
Drying Rates ◽  
Drying Curves ◽  
Kinetics Of

The objectives of this study were investigation the effects of microwave output powers on drying kinetics of yoghurt, selecting the best fitted thin-layer model to characterize the drying behavior of yoghurt and determination of the activation energy and effective diffusivity. In order to achieve these objectives, low-fat yoghurt was dried by using domestic microwave oven at different microwave output powers (100, 180 and 300 W). Average drying rates were determined as 1.49, 4.43 and 7.90 g H2O m-2 s-1 for microwave output powers of 100, 180 and 300 W, respectively. The effective moisture diffusivities were determined as 3.30 x 10-9, 6.62 x 10-9 and 1.15 x 10-8 m2 s-1 for 100, 180 and 300 W, respectively. The Ea of yoghurt was found as 3.62 W g-1. Midilli and others model was selected as best fitted model due to highest values of R2 and low values of χ2, RMSE and RSS.

scholarly journals Convective drying kinetics of osmotically pre-treated potato slices

2021 ◽  
Vol 25 (1) ◽  
pp. 13-15
Author(s):  
Vangelce Mitrevski ◽  
Cvetanka Mitrevska ◽  
Mirko Babić ◽  
Tale Geramitcioski ◽  
Borce Mitrevski
Keyword(s):  
Drying Kinetics ◽  
Thin Layers ◽  
Convective Drying ◽  
Material Loss ◽  
Data Set ◽  
Air Temperatures ◽  
Thin Layer Drying ◽  
Chi Squared ◽  
Kinetics Of ◽  
Potato Slices

In the food industry, convective drying is a widely used method due to its applicability to many food materials. Besides this advantage of the convective drying method, there are several shortcomings related to the rehydration capacity, low quality of dried material, loss of color, flavour, and nutrient of the final dried materials. In this paper, the convective drying kinetics of osmotically pre-treated potato slices (variety Carrera) were analyzed. Thin-layer drying kinetics of potato slices at four drying air temperatures 40, 50, 60 and 70°C and two drying air velocities 1 and 2 ms-1 were obtained on the experimental setup. For an approximation of the experimental data with regard to the moisture ratio three thin-layers drying, models from scientific literature and the model of Mitrevski et al., were used. For each model and data set the statistical performance index, ph chi-squared, and ch2, values were calculated and models were ranked afterward.

Mathematical Modeling of Thin-Layer Solar Drying for Yarrow, Coriander and Hollyhock

2015 ◽  
Vol 11 (5) ◽  
pp. 691-700 ◽  
Author(s):  
Yasaman Amanlou ◽  
Teymour Tavakoli Hashjin ◽  
Barat Ghobadian ◽  
Gholamhassan Najafi
Keyword(s):  
Theoretical Models ◽  
Drying Kinetics ◽  
Medicinal Products ◽  
Drying Process ◽  
Chi Square ◽  
Air Temperatures ◽  
C 50 ◽  
Drying Conditions ◽  
Kinetics Of ◽  
Best Fit

Abstract The objective of this study is to investigate the drying kinetics of Yarrow, Coriander and Hollyhock flowers. These three medicinal products were dried using a solar hybrid photovoltaic-thermal dryer. The drying process was examined at the air temperatures of 40°C, 50°C and 60°C and air velocities of 0.5, 1 and 1.5 m/s. The experimental drying data were fitted to different theoretical models to predict the drying kinetics. Nonlinear regression analysis was performed to relate the parameters of the model with the drying conditions. The performance of these models was evaluated by comparing the correlation coefficient ($${R^2}$$), root mean square error (RMSE) and the chi-square ($${\chi ^2}$$) between the observed and the predicted moisture ratios. Among all the models, the exponential two-term was found to have the best fit in this study. Also the influence of plant type, air temperature and velocity was investigated.

Drying Kinetics of Maize Cob Using Mathematical Modelling

2021 ◽  
Vol 58 (1) ◽  
pp. 40-49
Author(s):  
Pankaj Kumar ◽  
Dhritiman Saha
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Effective Diffusivity ◽  
Drying Kinetics ◽  
Drying Time ◽  
Drying Temperature ◽  
Page Model ◽  
Maize Cob ◽  
Kinetics Of ◽  
Maize Cobs

Maize cobs (with husk and without husk) with initial moisture content of 78.38 % and 62.39 % (d.b.), respectively, were dried up to 20 % moisture content (d.b.) at three temperatures (45°C, 55°C and 65°C). Moisture ratios (MR) were calculated from moisture loss data and fitted to six (Newton’s, Page, Thompson, Modified Page, Henderson and Pabis, and Wang and Singh) drying mathematical models. Coefficient of determination (R2) and root mean square error (RMSE) were used for comparison of the models. From the analyses, Modified Page model showed the best fit to the experimental data with R2 varying from 0.9924 to 0.9968 for maize cob with husk and 0.9994 to 9989 for cobs without husk at given drying temperatures. The Modified Page model was found to be a superior model representing the drying kinetics of maize cob with and without husk at drying temperatures of 45, 55, and 65°C. The increase in drying temperature caused a reduction in drying time, and the drying took place in the falling rate period. Maize cobs with husk took more time for drying as compared to that without husk at the same temperature. The values of effective diffusivity lied between 1.079×10-8 m2.s-1 and 4.239×10-8 m2.s-1 for maize cob with husk, and between 1.194×10-8 m2.s-1 and 5.230×10-8 m2.s-1 for maize cob without husk. Effective diffusivity increased with an increase in drying temperature and was higher for maize cob without husk than that of with husk

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