scholarly journals The Effect of Ultrasonic Pre-Treatment on the Temperature Controlled Infrared Drying of Loligo Vulgaris and Comparison with the Microwave Drying

2020 ◽  
Vol 21 (03) ◽  
pp. 135-145
Author(s):  
Zehra Ozden Ozyalcin ◽  
Azmi Seyhun Kipcak
Keyword(s):  
Microwave Drying ◽  
Coefficient Of Determination ◽  
Drying Time ◽  
Ultrasonic Pretreatment ◽  
Color Changes ◽  
Loligo Vulgaris ◽  
Rate Period ◽  
Pre Treatment ◽  
Drying Curves ◽  
Best Fit

In this study the effect of ultrasonic pre-treatment (US-IR) on the thin-layer infrared (IR) drying kinetics and modelling of Loligo Vulgaris (Squid) were studied and obtained data were compared with the microwave drying (MW). In each three methods, effective moisture diffusivities (Deff) and activation energies (Ea) were determined. According to the drying curves Loligo Vulgaris the highest drying times were found in IR and the lowest drying times were found in MW methods. Therefore, ultrasonic pretreatment decreased the drying times. Drying takes place in the falling-rate period generally. Midilli & Kucuk model best fit the experimental data for each method with the coefficient of determination (R2) values higher than 0.995. Highest Deff values were found in MW method and calculated between 1.25x10-8 - 5.62x10-8 m2/s, and the lowest Deff values were found in IR method and calculated between 6.57 × 10-10 - 1.35 × 10-9 m2/s. Moreover, Ea values were found 35.20 and 37.12 kJ/mol for IR and US-IR, and 35.43 for MW methods. Drying time, temperature and power levels lead to color changes.

scholarly journals Artificial Neural Network Modeling of Drying Kinetics and Color Changes of Ginkgo Biloba Seeds during Microwave Drying Process

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Jun-Wen Bai ◽  
Hong-Wei Xiao ◽  
Hai-Le Ma ◽  
Cun-Shan Zhou
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Ginkgo Biloba ◽  
Drying Kinetics ◽  
Microwave Drying ◽  
Drying Process ◽  
Drying Time ◽  
Color Changes ◽  
Rate Period ◽  
Artificial Neural

Ginkgo biloba seeds were dried in microwave drier under different microwave powers (200, 280, 460, and 640 W) to determinate the drying kinetics and color changes during drying process. Drying curves of all samples showed a long constant rate period and falling rate period along with a short heating period. The effective moisture diffusivities were found to be 3.318 × 10−9 to 1.073 × 10−8 m2/s within the range of microwave output levels and activation energy was 4.111 W/g. The L⁎ and b⁎ values of seeds decreased with drying time. However, a⁎ value decreased firstly and then increased with the increase of drying time. Artificial neural network (ANN) modeling was employed to predict the moisture ratio and color parameters (L⁎, a⁎, and b⁎). The ANN model was trained for finite iteration calculation with Levenberg-Marquardt algorithm as the training function and tansig-purelin as the network transfer function. Results showed that the ANN methodology could precisely predict experimental data with high correlation coefficient (0.9056–0.9834) and low mean square error (0.0014–2.2044). In addition, the established ANN models can be used for online prediction of moisture content and color changes of ginkgo biloba seeds during microwave drying process.

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.

The thin-layer drying characteristics of sewage sludge by the appropriate foaming pretreatment

2014 ◽  
Vol 69 (9) ◽  
pp. 1859-1866 ◽  
Author(s):  
Hui-Ling Wang ◽  
Zhao-Hui Yang ◽  
Jing Huang ◽  
Li-Ke Wang ◽  
Cheng-Liu Gou ◽  
...  
Keyword(s):  
Sample Thickness ◽  
Coefficient Of Determination ◽  
Drying Rate ◽  
Drying Time ◽  
Drying Characteristics ◽  
Thin Layer Drying ◽  
Dewatered Sludge ◽  
Drying Curves ◽  
Sludge Drying ◽  
The Impact

As dewatered sludge is highly viscous and sticky, the combination of foaming pretreatment and drying process seems to be an alternative method to improve the drying performance of dewatered sludge. In this study, CaO addition followed by mechanical whipping was employed for foaming the dewatered sludge. It was found that the foams were stable and the diameters of bubbles mainly ranged from 0.1 to 0.3 mm. The drying experiments were carried out in a drying oven in the convective mode. The results indicated that foamed sludge at 0.70 g/cm3 had the best drying performance at each level of temperature, which could save 35–45% drying time to reach 20% moisture content compared with the non-foamed sludge. The drying rate of foamed sludge at 0.70 g/cm3 was improved with the increasing of drying temperature. The impact of sample thickness on drying rate was not obvious when the sample thickness increased from 2 to 8 mm. Different mathematical models were used for the simulation of foamed sludge drying curves. The Wang and Singh model represented the drying characteristics better than other models with coefficient of determination values over 0.99.

scholarly journals Effects of Infrared-Assisted Refractance Window™ Drying on the Drying Kinetics, Microstructure, and Color of Physalis Fruit Purée

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 343
Author(s):  
Luis Puente-Díaz ◽  
Oliver Spolmann ◽  
Diego Nocetti ◽  
Liliana Zura-Bravo ◽  
Roberto Lemus-Mondaca
Keyword(s):  
Statistical Tests ◽  
Coefficient Of Determination ◽  
Drying Process ◽  
Chi Square ◽  
Ir Radiation ◽  
Drying Time ◽  
Drying Curves ◽  
Effective Diffusivities ◽  
Drying Conditions ◽  
Fruit Purée

The objective of this work was to study the influence of the drying temperature, infrared (IR) radiation assistance, and the Mylar™ film thickness during Physalis fruit purée drying by the Refractance Window™ (RW™) method. For this, a RW™ dryer layout with a regulated bath at working temperatures of 60, 75, and 90 °C, Mylar™ thicknesses of 0.19, 0.25, 0.30 mm and IR radiation of 250 W for assisting RW™ drying process was used. Experimental curves data were expressed in moisture ratio (MR) in order to obtain moisture effective diffusivities (non-assisted RW™: Deff = 2.7–10.1 × 10−10 m2/s and IR-assisted RW™: Deff = 4.2–13.4 × 10−10 m2/s) and further drying curves modeling (Page, Henderson–Pabis, Modified Henderson–Pabis, Two-Term, and Midilli–Kucuk models). The Midilli–Kucuk model obtained the best-fit quality on experimental curves regarding statistical tests applied (Coefficient of Determination (R2), Chi-Square (χ2) and Root Mean Square Error (RMSE). Microscopical observations were carried out to study the RW™ drying conditions effect on microstructural changes of Physalis fruit purée. The main findings of this work indicated that the use of IR-assisted RW™ drying effectively accelerates the drying process, which achieved a decrease drying time around 60%. Thus, this combined RW™ process is strongly influenced by the working temperature and IR-power applied, and slightly by Mylar™ thickness.

Effect of Pretreatment Methods on the Moisture State and Drying Quality of Balsam Pear (Momordica charantia L.) Slices Using a Microwave Vibratory Fluidized Bed

2019 ◽  
Vol 15 (1-2) ◽  
Author(s):  
Hao Lv ◽  
Jiwei Ma ◽  
Weiqiao Lv ◽  
Huangzhen Lv ◽  
Dan Zhao ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Superheated Steam ◽  
Microwave Drying ◽  
Steam Pretreatment ◽  
Water Molecules ◽  
Drying Time ◽  
Color Changes ◽  
Drying Efficiency ◽  
Drying Quality

AbstractIn order to improve the uniformity of microwave absorption and obtain good drying quality, a vibratory fluidized bed was used during the microwave drying of balsam pear slices. The temperature distribution of the materials during drying is discussed. The water state and drying quality of the balsam pear slices with blanching, ultrasonic, and superheated steam pretreatment were measured using low-field nuclear magnetic resonance and scanning electron microscopy. As a result, the drying uniformity of balsam pear slices was improved, and the drying temperature decreased more than 10 °C using the microwave vibratory fluidized bed. By using an ultrasonic pretreatment step, the activity of the water molecules was improved, and the drying time was reduced by 10 min, but the product was discolored during drying. Blanching and superheated steam pretreatment did not improve the activity of water molecules, but the product color changes were minimal and drying time was reduced by 20 min. The microstructure of dehydrated balsam pear slices was destructed seriously caused by this heat–moist pretreatment. Therefore, a variety of pretreatments should be integrated for the comprehensive control of the processing characteristics, such as enzyme deactivation and improving water activity, to further improve the drying efficiency and quality of balsam pear slices.

scholarly journals Modelling the Drying Characteristics and Kinetics of Hot Air-Drying of Unblanched Whole Red Pepper and Blanched Bitter Leaf Slices

2017 ◽  
Vol 5 (1) ◽  
pp. 24
Author(s):  
Samuel Enahoro Agarry
Keyword(s):  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Red Pepper ◽  
Coefficient Of Determination ◽  
Drying Time ◽  
Drying Characteristics ◽  
Hot Air ◽  
Effective Moisture ◽  
Drying Curves ◽  
Kinetics Of

The objective of this study was to investigate the drying characteristics and kinetics of red pepper and bitter leaf under the influence of different drying temperatures. The drying experiments were carried out at dry bulb temperature of 35, 45, 55 and 75oC, respectively in an oven dryer. The results showed that as drying temperature increased, drying rate also increased and the drying time decreased. It was observed that un-sliced red pepper and sliced bitter leaf would dry within 2.5-12 h and 1.67-7 h, respectively at temperature ranging from 75 to 35oC. The drying of red pepper and bitter leaf was both in the constant and falling rate period. Four semi-empirical mathematical drying models (Newton, Page, Henderson and Pabis, and Logarithmic models) were fitted to the experimental drying curves. The models were compared using the coefficient of determination (R^2) and the root mean square error (RMSE). The Page model has shown a better fit to the experimental drying data of red pepper and bitter leaf, respectively as relatively compared to other tested models. Moisture transport during drying was described by the application of Fick’s diffusion model and the effective moisture diffusivity was estimated. The value ranges from 15.69 to 84.79 × 10-9 m2/s and 0.294 to 1.263 × 10-9 m2/s for red pepper and bitter leaf, respectively. The Arrhenius-type relationship describes the temperature dependence of effective moisture diffusivity and was determined to be 37.11 kJ/mol and 32.86 kJ/mol for red pepper and bitter leaf, respectively. A correlation between the drying time and the heat transfer area was also developed.

scholarly journals Thin Layer Mathematical Modelling of Cob Maize in a Natural Convection Solar Drier

2017 ◽  
Vol 7 (2) ◽  
pp. 37
Author(s):  
M Mukwangole ◽  
I. N. Simate
Keyword(s):  
Natural Convection ◽  
Relative Humidity ◽  
Moisture Content ◽  
Coefficient Of Determination ◽  
Drying Time ◽  
Ambient Relative Humidity ◽  
Safe Level ◽  
Content Ratio ◽  
Drying Curves ◽  
Maize Cobs

A semi- cylindrical natural convection solar tunnel drier (STD) was used for experiments to dry maize cobs that were partially field- dried. The air temperature recorded in the collector unit was higher than ambient temperature by 15.8oC to 20.8oC and this was effective in reducing the moisture content of maize cobs from 30 % wet basis to safe level storage moisture content of 12.5 % wet basis. Averages of solar radiation recorded during the experiments ranged from 585.6 W/m2 to 759.8 W/m2. The averages of relative humidity that prevailed in the drying unit ranged from 6.8 % to 18.2 % whereas the ambient relative humidity averaged from 27.3 % to 43.7 %. Drying time was examined with moisture content ratio as exponential and polynomial correlations. Fourteen different drying mathematical models available in literature were compared using their coefficients of determination to estimate solar drying curves. Based on statistical analysis of the results, Midilli drying model had the best fit to the experimental drying data of maize with a coefficient of determination R2= 0.99912 as compared to other models. 

scholarly journals Effect of Microwave Drying on the Drying Characteristics, Color, Microstructure, and Thermal Properties of Trabzon Persimmon

Foods ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 84 ◽  
Author(s):  
Soner Çelen
Keyword(s):  
Energy Consumption ◽  
Color Change ◽  
Power Level ◽  
Effective Diffusion ◽  
Microwave Energy ◽  
Microwave Drying ◽  
Slice Thickness ◽  
Fresh Sample ◽  
Drying Time ◽  
Color Changes

In this study, changes in the drying kinetics, color change, and the energy consumption for microwave energy were investigated for Trabzon persimmon. In addition to that, the microstructure of the persimmon was also investigated by considering its thermal changes. It is important to be aware of the purpose of the drying process for determining the drying system. Results of this research showed that 460 W for 7 mm slice thickness depending on energy consumption, 600 W for 5 mm slice thickness depending on drying time, and 600 W depending on color changes were found as suitable drying processes depending on drying conditions. The effective diffusion values varied between 2.97 × 10−8 m2 s−1 and 4.63 × 10−6 m2 s−1. The activation energy values for 5 mm, 7 mm and 9 mm slice thickness were estimated as 32.82, 18.64, and 12.80 W g−1, respectively. The drying time and energy consumption decreased, whereas drying rate increased with an increase in the microwave energy. The number of pores increased compared to structure of fresh sample, and the pores got to be larger for 5 mm slice thickness as the power level increased. Results showed that the applied microwave energy had an important effect on the heating of the material and the change in the microstructure.

scholarly journals Effect of pre-treatments on solar drying kinetics of red seedless grapes (cv. Monukka)

2014 ◽  
Vol 3 (2) ◽  
Author(s):  
Inês Nunes Ramos ◽  
Teresa R.S. Brandão ◽  
Cristina L.M. Silva
Keyword(s):  
Edible Oil ◽  
Hot Water ◽  
Drying Time ◽  
Water Emulsion ◽  
Oil Emulsion ◽  
Oil Water ◽  
Drying Rates ◽  
Drying Curves ◽  
Kinetics Of ◽  
Best Fit

Two different pre-treatments were applied to grapes prior to drying in a mixed mode solar dryer. Grapes were blanched in water and in a 0.1% sunflower oil water emulsion, both at 99oC and for approximately 15 seconds. Several models were tested to fit the experimental data of drying curves but the normalized Newton model gave the best fit results. Samples blanched in hot water or in the 0.1% edible oil emulsion had faster drying rates than untreated samples. Contrary to what was expected, pre-treating with the 0.1% edible oil emulsion did not increase the drying rate to a higher extent than blanching. Pre-treatments did not give a noteworthy difference in the total drying time. However, they had an important role in accelerating initial drying rates, thus preventing moulds and bacterial growth and consequently increasing farmers’ income.

scholarly journals Drying kinetics of atemoya pulp

2016 ◽  
Vol 20 (7) ◽  
pp. 672-677 ◽  
Author(s):  
Plúvia O. Galdino ◽  
Rossana M. F. de Figueirêdo ◽  
Alexandre J. de M. Queiroz ◽  
Pablícia O. Galdino
Keyword(s):  
Mixing Time ◽  
Theoretical Models ◽  
Coefficient Of Determination ◽  
Drying Method ◽  
Content Ratio ◽  
Different Temperatures ◽  
Forced Air ◽  
Drying Curves ◽  
Kinetics Of ◽  
Best Fit

ABSTRACT This study was conducted in order to obtain drying curves of whole atemoya pulp through the foam-mat drying method. The suspension was prepared with whole atemoya pulp mixed with 2% of Emustab® and 2% of Super Liga Neutra® with mixing time of 20 min, and dried in a forced-air oven at different temperatures (60; 70 and 80 °C) and thicknesses of the foam layer (0.5, 1.0 and 1.5 cm). The drying rate curves were plotted against the water content ratio and the semi-theoretical models of Henderson & Pabis, Page and Midilli were used. All tested models showed coefficient of determination (R2) above 0.993, and the Midilli model showed the best fit for all conditions. Drying curves were affected by temperature and layer thickness.

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