Mathematical Modeling and Experimental Study on Thin Layer Drying of Strawberry

This paper presents thin layer modeling of ogi produced from yellow and white maize at varying soaking period and dried in the cabinet and oven at 50 ºC. The moisture decrease for cabinet dried ogi produced from white maize from 49.0 11.5%, 49.5 to 11.32%, 46.5 to 12.33% and 46.12.29%. The drying rate for both oven and cabinet dried ogi produced from yellow maize decreased from 4.6 to 0.0525 kg/min, 4.5 to 0.0513 kg/min, 4.35 to 0.049 kg/min and 4.4 to 0.047 kg/min while for oven dried ogi followed a similar trend. The experimental data obtained were fitted to five thin layer models: Newton, Page, Herderson and Pabis, Two term and Wingh and Singh models. The values obtained for ogi produced from white maize and dried in the cabinet and oven at 50 ºC for Newton model gave a lower R2, ?2, RMSE compared with respective values obtained from Page, Herderson and Pabis, two term, Wing and Singh models. The two terms model appear to be the best model among the five models used in this work and had higher R2, lower ?2, and RMSE. The ogi produced from yellow maize at varying soaking period of 24, 48, 72 and 96 hours and dried in cabinet dryer and fitted with two term showed model constants a, K0, b, K1 0.04315, 0.0388995, 0.919, 2.2 × 10-3 while the R2, ?2 RMSE were 0.9933, 5.85 × 10-4 and 4.85 × 105 for ogi produced for 24 hours soaking, respectively. The soaking period does not seem to affect the moisture ratio and the thin layer drying model. However, the initial moisture and equipment seems to affect significantly.

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Improved protocol for natural convection pumpkin drying

Food and Feed Research ◽

10.5937/ffr0-31341 ◽

2021 ◽

pp. 29-39

Author(s):

Hakim Semai ◽

Amor Bouhdjar ◽

Aissa Amari

Keyword(s):

High Temperature ◽

Effective Diffusivity ◽

Convective Drying ◽

Agricultural Product ◽

Diffusivity Coefficient ◽

Drying Time ◽

Thin Layer Drying ◽

Different Temperatures ◽

Energy Consuming ◽

Drying Curves

The most effective way to preserve agricultural product is drying. However, vegetable drying is an energy-consuming procedure. Convective drying is the mode considered in this work. The study intends to explore a new way of pumpkin drying, which reduces drying time and minimizes heat consumption. The study considers pumpkin thin slices and pumpkin samples with cubic shape. The samples were subjected to free convection airflow at different temperatures (40 °C, 46 °C, 52 °C, and 60 °C) for each run. A varying airflow temperature was also considered. Airflow velocity was generated by buoyancy forces for each temperature. Drying curves were plotted and fitted to the widely used thin-layer drying models. The modified Page model came out as the best-fitted model. The effective diffusivity coefficient was determined for each case using the slope moisture curve. It appeared that diffusivity was high and drying time was short, for high temperature. Drying processes for slice configuration and cube configuration showed that the latter was more efficient. When applying the regime of increasing temperatures to the cubic samples, data analysis showed that effective diffusivity was higher during the third step in comparison to all the other drying temperatures and the total drying time was similar to that obtained at drying regime on high temperature. With this procedure, the final consumed energy was much less and the time was shorter.

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

Research in Agricultural Engineering ◽

10.17221/42/2011-rae ◽

2012 ◽

Vol 58 (No. 2) ◽

pp. 73-82 ◽

Cited By ~ 6

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°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 (R2) was high for all drying cases. The computed values of Deff were between 3.38 × 10–10 and 2.54 × 10–9 m2/s during the falling rate drying. Values of Deff 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°C, respectively. The specific energy consumption (SEC) for garlic specimens was placed in the range of 0.316 × 106 and 0.979 × 106 kJ/kg from 50 to 80°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°C was suitable to produce dried garlic.

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Mathematical Modeling of a Cross-Flow Rice Dryer with Grain Inverters

Transactions of the ASABE ◽

10.13031/trans.12927 ◽

2018 ◽

Vol 61 (5) ◽

pp. 1757-1765

Author(s):

Bhagwati Prakash ◽

Terry J. Siebenmorgen

Keyword(s):

Mathematical Modeling ◽

Thin Layer ◽

Air Temperature ◽

Cross Flow ◽

Grain Moisture ◽

Thin Layer Drying ◽

Model Predictions ◽

Page Equation ◽

Drying Conditions ◽

The Impact

Abstract. Industrial-scale cross-flow dryers are commonly equipped with grain inverters to improve the uniformity of drying across the column thickness. While a few mathematical models have been reported that include the operation of grain inverters, such models were rarely validated with experiments comprising grain inversions. In this study, a mathematical model was developed to evaluate the impact of grain inverters on the uniformity of grain moisture content (MC) across the column in cross-flow dryers. To improve the accuracy of model predictions, the impact of using two thin-layer drying equations, the Newton and modified Page equations, in the model was also investigated. An experimental setup was fabricated to simulate grain inversion, and drying experiments were performed to measure rice MC and air temperature across the column thickness, which were then compared with model-predicted values. When the modified Page equation was used in the model, the model predictions matched the experimental observations more closely than when using the Newton equation. The model successfully predicted grain and air properties when 0, 1, and 2 grain inversions were used; the root mean square error between predicted and measured values of rice MC and air temperature were within 0.1 to 0.2 percentage points and 1°C to 4°C, respectively. Grain inversions were shown to improve the uniformity of drying in rice kernels; in the tested drying conditions, a single grain inversion produced more uniform drying than two or more grain inversions in the column. The presented results demonstrate the usefulness of the developed model in investigating the role of grain inversion in cross-flow drying of rice. As such, the model could be readily used to improve dryer design, particularly the number and arrangement of grain inverters, and optimize rice drying operations. Keywords: Deep-bed drying, Grain inverters, Mathematical modeling, Reversed airflow, Thin-layer drying.

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An improved protocol for natural convective drying of pumpkin

Food and Feed Research ◽

10.5937/ffr48-31341 ◽

2021 ◽

Vol 48 (1) ◽

pp. 29-39

Author(s):

Hakim Semai ◽

Amor Bouhdjar ◽

Aissa Amari

Keyword(s):

High Temperature ◽

Effective Diffusivity ◽

Convective Drying ◽

Agricultural Product ◽

Diffusivity Coefficient ◽

Drying Time ◽

Thin Layer Drying ◽

Different Temperatures ◽

Energy Consuming ◽

Drying Curves

The most effective way to preserve agricultural product is drying. However, vegetable drying is an energy-consuming procedure. Convective drying is the mode considered in this work. The study intends to explore a new way of pumpkin drying, which reduces drying time and minimizes heat consumption. The study considers pumpkin thin slices and pumpkin samples with cubic shape. The samples were subjected to free convection airflow at different temperatures (40 °C, 46 °C, 52 °C, and 60 °C) for each run. A varying airflow temperature was also considered. Airflow velocity was generated by buoyancy forces for each temperature. Drying curves were plotted and fitted to the widely used thin-layer drying models. The modified Page model came out as the best-fitted model. The effective diffusivity coefficient was determined for each case using the slope moisture curve. It appeared that diffusivity was high and drying time was short, for high temperature. Drying processes for slice configuration and cube configuration showed that the latter was more efficient. When applying the regime of increasing temperatures to the cubic samples, data analysis showed that effective diffusivity was higher during the third step in comparison to all the other drying temperatures and the total drying time was similar to that obtained at drying regime on high temperature. With this procedure, the final consumed energy was much less and the time was shorter.

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Thin Layer Drying Characteristics of Eriste: A Dried Cereal Product of Turkey

International Journal of Food Engineering ◽

10.2202/1556-3758.1188 ◽

2008 ◽

Vol 4 (2) ◽

Cited By ~ 2

Author(s):

Ayhan Duran ◽

Ali Adnan Hayaloglu ◽

Ihsan Karabulut

Keyword(s):

Thin Layer ◽

Air Temperature ◽

Effective Diffusivity ◽

Sample Thickness ◽

Suitable Model ◽

Sample Weight ◽

Drying Characteristics ◽

Thin Layer Drying ◽

Cereal Product ◽

Drying Curves

Effect of air temperature (50, 60 and 70 °C) and sample thickness (1.0, 1.4 and 1.8 mm) on the thin-layer drying characteristics of eriste was studied by using a tray dryer. The data of sample weight, dry and wet-bulb temperatures were recorded continuously during each experiment and drying curves were obtained. The drying curves were then fitted to five mathematical models available in the literature to estimate a suitable model for drying of eriste. Verma et al. model gave better predictions than other models and satisfactorily described the thin layer characteristics of eriste. The effective diffusivity varied from 1.8 x exp-10 to 1.5 x exp-9 m2 s-1 over the temperature range.

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MATHEMATICAL MODELING OF THIN LAYER DRYING OF CANOLA PODS

Journal of Soil Sciences and Agricultural Engineering ◽

10.21608/jssae.2012.53861 ◽

2012 ◽

Vol 3 (2) ◽

pp. 297-312

Author(s):

A. M. Matouk ◽

H. N. Abd El-Mageed ◽

A. Tharwat ◽

S. E. El-Far

Keyword(s):

Mathematical Modeling ◽

Thin Layer ◽

Thin Layer Drying

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Effect of Pre-Treatment on the Drying Characteristics and Kinetics of Okra (Abelmoschus esculetus (L.) Moench) Slices

International Journal of Food Engineering ◽

10.2202/1556-3758.1191 ◽

2009 ◽

Vol 5 (2) ◽

Cited By ~ 13

Author(s):

Olajide Sobukola

Keyword(s):

Air Temperature ◽

Sample Thickness ◽

Hot Water ◽

Drying Rate ◽

Diffusivity Coefficient ◽

Drying Characteristics ◽

Rate Period ◽

Pretreatment Conditions ◽

Air Dryer ◽

Kinetics Of

The effects of air temperature (50, 60 and 70°C), sample thickness (2, 4 and 6mm) and pretreatment conditions (hot water blanching, 1 and 3% sodium metabisulphite solutions) on the drying characteristics and kinetics of okra were investigated using a convective hot air dryer at a flow rate of 1.5m/s. It was observed that pretreatment conditions, sample thickness and drying air temperature significantly (P<0.05) affected drying rate. Drying rate increases as temperature of drying air increases from 50 to 70°C. The drying curve for all experiments occurred in the falling rate period with no constant rate period. Three thin layer drying models (Page, modified Page I and Wang and Singh) were evaluated using coefficient of determination (R2), root mean square error (RMSE) and the reduced chi square (?2). The three models can appropriately describe the drying kinetics of okra slices considering the different experimental conditions. The effective diffusivity was determined using the Ficks model and was observed to vary between 1.125x10-8 9.93x10-9m2/s and 1.165x10-8 7.131x10-9 m2/s for treated and untreated samples. The Arrhenius-type relationship describes the temperature dependence of diffusivity coefficient and was determined to be 16.749kJ/mol and 22.437kJ/mol for treated and untreated samples respectively.

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