scholarly journals Experimental Research of Drying Characteristics of Red Banana in a Single Slope Solar Dryer Based on Natural and Forced Convection

2021 ◽  
Vol 59 (2) ◽  
Author(s):  
Elavarasan Elangovan ◽  
Sendhil Kumar Natarajan
Keyword(s):  
Activation Energy ◽  
Correlation Coefficient ◽  
Forced Convection ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Solar Drying ◽  
Solar Dryer ◽  
Proposed Model ◽  
Thin Layer Drying ◽  
Drying Technology

Research background. Traditionally, open sun drying method is used to dry the products for long time preservation. For the same products, solar drying technology is being employed to minimize the drying time for achieving the required moisture content. This solar drying technology, which inherently contains complex heat and mass transfer mechanism, which makes difficult to describe drying kinetics at the micro level. Experimental approach. In this present paper, research work is carried out to investigate the drying of 5 mm thickness of red banana (Musa acuminata “Red Dacca”) in a single slope solar dryer based on natural and forced convection. Based on the experiments, development of new semi-empirical thin layer drying kinetics correlation for red banana is proposed. The proposed correlation is also compared with other existing models. The proposed model is in very good agreement with well-known other models and the correlation coefficient (R2) of 0.997 is obtained. Based on the model, the moisture diffusivity and activation energy of the red banana are also obtained. Results and conclusions. It is found that, the moisture diffusivity of the red banana samples is in the range of 8.74·10-10-1.56·10-9 m2/s for natural convection solar drying and 8.43·10-9-2.61·10-8 m2/s for forced convection solar drying. The activation energy of the red banana is varied from 24.58 to 45.20 kJ/mol for passive mode and 22.56 to 35.49 kJ/mol for active mode. Besides, energy and exergy analysis of red banana in a dryer are also carried out. It is found that the average exergy losses for the forced and natural convections are obtained as 16.1 kJ/kg and 6.63 kJ/kg and the average exergic efficiency for the natural and forced convection dryer was obtained as 57.7 % and 70.9 %, respectively. Novelty and scientific contribution. A single slope direct type solar dryer was designed and fabricated to maintain the desired temperature for a specified period in both natural and forced convection phenomena. A novel drying kinetics model is proposed to preserve red banana. The proposed model given a superior correlation coefficient (R2) when compared to other drying kinetics models.

Solar Drying of Ivy Gourd: Influence of Various Dipping Solutions on Activation Energy and Moisture Diffusivity

2021 ◽  
Author(s):  
Elavarasan Elangovan ◽  
Gulivindala Anil Kumar
Keyword(s):  
Activation Energy ◽  
Ascorbic Acid ◽  
Shelf Life ◽  
Forced Convection ◽  
Moisture Diffusivity ◽  
Sugar Solution ◽  
Solar Drying ◽  
Drying Method ◽  
Drying Process ◽  
Ivy Gourd

Abstract The study is aimed to enhance the shelf life of ivy gourd through solar drying method in open, forced and natural convection mode. Ivy gourd is treated as primary agent to prepare medicines and the stems, leaves; flowers are used to cure the diseases related diabetics, ulcer, skin. The normal shelf life is 2-3 days and it can be increased up to 6 months with an effective drying process. The experiment is intended to find the best drying process among the open, natural and forced convection mode with an initial dipping method with ascorbic acid, lemon juice, sugar solution, honey solutions individually and a control sample (without dipping). A 3kg sample of ivy gourd is dipped in 10g/L of the each of the solution and it is used for the three drying process individually. The obtained results are indicating that forced convection method for ascorbic acid is best among the other drying method with highest moisture diffusivity is 7.88×10-8 m2/s and lowest activation energy 21.12 kJ/mol. It was observed that the drying kinetics of ivy gourd should be considered an indicator of efficiency for solar drying technique from environmental safety perspective. The influence of dipping solution and drying mechanisms on the functionalities of drying are discussed with suitable illustrations.

Modeling Thin Layer Drying Kinetics, Moisture Diffusivity and Activation Energy of Hazelnuts during Microwave-Convective Drying

2017 ◽  
Vol 14 (2) ◽  
Author(s):  
Narjes Malekjani ◽  
Zahra Emam-Djomeh ◽  
Seyed Hassan Hashemabadi ◽  
Gholam Reza Askari
Keyword(s):  
Activation Energy ◽  
Microwave Power ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Drying Method ◽  
Drying Process ◽  
Dominant Effect ◽  
Thin Layer Drying ◽  
Kinetics Of

AbstractThe effects of microwave-convective drying as an efficient drying method, on drying kinetics of hazelnuts were studied. Drying experiments were conducted at three temperature (40, 50 and 60°C) and microwave power (0, 450 and 900 W) levels. The moisture ratio and the temperature of the hazelnuts were recorded during the drying. The results showed that microwave power had a more dominant effect than drying air temperature. Mathematical modeling was performed in order to predict the moisture changes during drying process. It was concluded that two term and Midilli et al. models were the best models to predict the drying kinetics of hazelnut in different conditions. The effective moisture diffusivities varied from 3.80327×10‒8to 1.71233×10‒6m2/s and had an increasing polynomial relationship with temperature and microwave power. The activation energy was also between 15.61675 and 41.0053 kJ/mol with a second-order relationship with microwave power.

HOT-AIR DRYING AND MODELING THE DRYING KINETICS OF SUNFLOWER (HELIANTHUS ANNUS L.) PETALS

2020 ◽  
Vol 23 (3) ◽  
Author(s):  
Amir Hossein Mirzabe ◽  
◽  
Gholam Reza Chegini ◽  
Keyword(s):  
Economic Value ◽  
Cost Effective ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Sunflower Seeds ◽  
Hot Air ◽  
Thin Layer Drying ◽  
Helianthus Annus ◽  
Air Dryer ◽  
Kinetics Of

Sunflower seeds and oil in food and agricultural processing are of great importance. Dried sunflower petals are the most important parts of the sunflower plant that have economic value. Thin-layer drying experiments were performed in a laboratory scale hot-air dryer. The results indicated that with increasing drying temperature and air velocity, time of drying reduces and in most cases, the logarithmic model had the best performance for modeling the drying kinetics. The calculated values of the effective moisture diffusivity varied from 3.16627 ×10-13 to 1.32860 ×10-12 m2 s-1 and the values of the activation energy for air velocities of 0.4 and 0.8 m s-1 were equal to 51.21 and 42.3 kJ mol-1, respectively. Also, to verify whether the production and sale of sunflower petals can be cost effective, economic analysis was done. This analysis showed that drying of sunflower petals is profitable process and the generated revenue can even surpass the revenue from the sale of sunflower seeds.

scholarly journals Comparative study of different drying methods regard to the phenols and flavonoids content of dried Citrus aurantium L. leaves

2021 ◽  
Author(s):  
Geovanni Hernandez Galvez ◽  
Margarita Castillo Téllez ◽  
Jorge de Jesús Chan González ◽  
Francisca Méndez Morales ◽  
Damianys Almenares López ◽  
...  
Keyword(s):  
Natural Convection ◽  
Forced Convection ◽  
Design Methodology ◽  
Total Phenol ◽  
Drying Methods ◽  
Total Flavonoids ◽  
Citrus Aurantium ◽  
Solar Drying ◽  
Solar Dryer ◽  
Total Flavonoids Content

Objective: To determine the effects of different thermal drying technologies on the total phenol and flavonoid contents (TPC) and total flavonoids (TFC) in sour orange (Citrus aurantium L.) leaves. Design/methodology/approach: Solar drying was carried out in outdoor sunny conditions using two direct solar dryers; one with natural convection, the other with forced convection. The total phenol and flavonoid contents in gallic acid equivalents (GAE) and quercetin (Q), respectively, of ethanolic extracts of C. aurantium were assessed with spectrophotometric techniques. Results: The results demonstrated maximum phenol values for the direct natural convection solar dryer (161.4 mg EAG/g MS) and minimum values for shade drying (61.43 mg EAG/g MS). As for flavonoids, the highest values were obtained in the direct forced convection solar dryer (32.22 ± 1.6 mg EQ/g MS), while the lowest was registered in the open air sun (11.72 mg EQ/g MS). Conclusions: Direct solar dryers are technologies effective for maintaining the phenols and total flavonoids content in dried leaves of C. aurantium.  

scholarly journals Drying Modelling, Moisture Diffusivity and Sensory quality of Thin Layer dried Beef

2018 ◽  
Vol 6 (2) ◽  
pp. 552-565 ◽  
Author(s):  
Eunice Akello Mewa ◽  
Michael Wandayi Okoth ◽  
Catherine Nkirote Kunyanga ◽  
Musa Njue Rugiri
Keyword(s):  
Thin Layer ◽  
Sensory Quality ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Effect Of Temperature ◽  
Slice Thickness ◽  
Drying Time ◽  
Drying Characteristics ◽  
Thin Layer Drying

The objective of the present study was to determine the drying kinetics, moisture diffusivity and sensory quality of convective air dried beef. The effect of temperature of drying (30-60°C) and thickness of samples (2.5-10 mm) on the convective thin-layer drying kinetics of beefdried in a cabinet dryer was evaluated. Five semi-theoretical models were fit to the drying experimentaldata with the aim of predicting drying characteristics of beef and fitting quality of models determined using the standard error of estimate (SEE)and coefficient of determination (R2). Determination ofeffective moisture diffusivity (Deff) from the experimental drying datawas done and sensory quality of the optimized dried cooked and uncookedbeef samplesevaluated. Drying time and rate of drying increased with an increasing temperature but decreased with increased slice thickness. However, there was overlapping of drying curves at 40-50°C. Among the selected models, Page model gave the best prediction of beef drying characteristics. Effective moisture diffusivity (Deff) ranged between 4.2337 x 10-11 and 5.5899 x 10-10 m2/s, increasing with an increase in air temperature and beef slice thickness.Of all the sensory parameters evaluated, texture was the only attribute that gave significantly different (P > 0.05) scores between the cooked and uncooked dried beef samples.

Mathematical Modelling of Thin Layer Sun and Solar Drying of Cassava Chips

2010 ◽  
Vol 6 (6) ◽  
Author(s):  
Toyosi Y Tunde-Akintunde
Keyword(s):  
Thin Layer ◽  
Correlation Coefficients ◽  
Moisture Diffusivity ◽  
Solar Drying ◽  
Drying Time ◽  
Drying Characteristics ◽  
Page Model ◽  
Thin Layer Drying ◽  
Rate Period ◽  
Pretreatment Conditions

In this paper, the effect of sun and solar drying and pretreatment conditions (soaking in water; soaking in water and then blanching; blanching and then soaking) on the drying characteristics and kinetics of cassava chips were investigated. The drying time was shorter for samples pretreated by soaking only (SK) compared to the others. It was observed that pretreatment conditions and drying method significantly (P < 0.05) affected the drying rate. The drying for all experiments occurred in the falling rate period with no constant rate period. Four mathematical models were studied for the description thin layer drying characteristics of pretreated cassava chips. The models considered were the Henderson and Pabis, Newton, Logarithmic and the Page model. Comparing the correlation coefficients (R2), chi-square (c2) and root mean square error (RMSE) values of four models, it was observed that the highest values of R2 and lowest ?2 and RMSE were obtained using Page model. This shows that the Page model represents drying characteristics better than other models. The effective moisture diffusivity values were estimated from Fick’s diffusional model. These values obtained for solar dried samples were generally higher than those obtained for sun dried samples.

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