Microwave Drying Kinetics, Hypericin Content, Effective Moisture Diffusivity and Activation Energy ofHypericum perforatumL.

To study the effect of microwave output power on the drying kinetics of tilapia fillets, the drying experiments were carried out at 150W, 250W, 500W, 700W and 900W, respectively. And ten mathematical models were involved to fit experimental data. It was found that Midilli et al model gave a best fitness for this conditions applied. Besides, effective moisture diffusivity increased progressively from 1.6248×10-9(m2/s) to 10.0735×10-9(m2/s) as the power increased from 150W to 900W. In addition, to obtain more homogeneous samples, temperature distribution of tilapia fillets was analyzed when they were put in different layout forms.

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Moisture Diffusivity and Energy Consumption during Microwave Drying of Plaster of Paris

Chemical Product and Process Modeling ◽

10.2202/1934-2659.1316 ◽

2010 ◽

Vol 5 (1) ◽

Cited By ~ 2

Author(s):

Magesh Ganesh Pillai ◽

Iyyasamy Regupathi ◽

Lima Rose Miranda ◽

Thanapalan Murugesan

Keyword(s):

Energy Consumption ◽

Initial Moisture Content ◽

Moisture Diffusivity ◽

Operating Conditions ◽

Microwave Drying ◽

Effective Moisture Diffusivity ◽

Experimental Conditions ◽

Drying Time ◽

Plaster Of Paris ◽

Effective Moisture

The drying characteristics of plaster of paris (POP) under microwave conditions at different microwave power input, initial moisture content, sample thickness and drying time were studied. Further the experimental data on moisture ratio of POP for different operating conditions were obtained and calculations were made using nine basic drying model equations. The appropriate model with modified constants and coefficients to represent the drying kinetics of POP was found through the analysis of the statistical analysis. The effective moisture diffusivity of the drying process was also computed for different experimental conditions and a relationship between the drying rate constant and the effective moisture diffusivity was obtained. The energy consumption for microwave drying of plaster of paris at different experimental conditions were also computed.

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Modelling Effective Moisture Diffusivity of Pumpkin (Cucurbita moschata) Slices under Convective Hot Air Drying Condition

International Journal of Food Engineering ◽

10.1515/ijfe-2015-0382 ◽

2016 ◽

Vol 12 (5) ◽

pp. 481-489 ◽

Cited By ~ 17

Author(s):

Daniel I. Onwude ◽

Norhashila Hashim ◽

Rimfiel B. Janius ◽

Nazmi Nawi ◽

Khalina Abdan

Keyword(s):

Activation Energy ◽

Moisture Diffusivity ◽

Effective Moisture Diffusivity ◽

Slice Thickness ◽

Cucurbita Moschata ◽

Drying Time ◽

Hot Air ◽

Effective Moisture ◽

Shrinkage Effect ◽

Increasing Temperature

Abstract This study seeks to investigate the effects of temperature (50, 60, 70 and 80 °C) and material thickness (3, 5 and 7 mm), on the drying characteristics of pumpkin (Cucurbita moschata). Experimental data were used to estimate the effective moisture diffusivities and activation energy of pumpkin by using solutions of Fick’s second law of diffusion or its simplified form. The calculated value of moisture diffusivity with and without shrinkage effect varied from a minimum of 1.942 × 10–8 m2/s to a maximum of 9.196 × 10–8 m2/s, while that of activation energy varied from 5.02158 to 32.14542 kJ/mol with temperature ranging from 50 to 80 °C and slice thickness of 3 to 7 mm at constant air velocity of 1.16 m/s, respectively. The results indicated that with increasing temperature, and reduction of slice thickness, the drying time was reduced by more than 30 %. The effective moisture diffusivity increased with an increase in drying temperature with or without shrinkage effect. An increase in the activation energy was observed due to an increase in the slice thickness of the pumpkin samples.

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Effect of Air Velocity and Temperature on the Drying Kinetics of Drumstick Leaves (Moringa Oleifera)

International Journal of Food Engineering ◽

10.1515/1556-3758.1986 ◽

2012 ◽

Vol 8 (4) ◽

Cited By ~ 9

Author(s):

Monica Premi ◽

Harish Sharma ◽

Ashutosh Upadhyay

Keyword(s):

Experimental Data ◽

Activation Energy ◽

Moringa Oleifera ◽

Moisture Diffusivity ◽

Drying Kinetics ◽

Drying Rate ◽

Air Velocity ◽

Drying Time ◽

Effective Moisture ◽

Kinetics Of

Abstract The present study examines the effect of air velocity on drying kinetics of the drumstick leaves in a forced convective dryer. The drumstick leaves were dried in the temperature range of 50–800 C, at different air velocity (Dv) of 0.5 and 1.3 m/s. The results indicated that drying temperature and air velocity are the factors in controlling the drying rate. Experimental data obtained for the samples for color, drying rate and drying time proved that air velocity of 1.3 m/s yielded the product superior in terms of both quality and energy efficiency as compared to the samples at 0.5 m/s. Activation energy for drumstick leaves dried with air velocity, 0.5 and 1.3 m/s was 12.50 and 32.74 kJ/mol respectively. The activation energy relates similarly with the effective moisture diffusivity which also increased with increase in air velocity and temperature.

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Mathematical modelling of diced konjac corms drying in a fluidised bed dryer

Thermal Science ◽

10.2298/tsci190704092m ◽

2020 ◽

Vol 24 (5 Part A) ◽

pp. 2833-2843

Author(s):

Montree Montreepila ◽

Nattapol Poomsa-Ad ◽

Lamul Wiset

Keyword(s):

Fluidized Bed ◽

Native Species ◽

Linear Regression Analysis ◽

Moisture Diffusivity ◽

Drying Kinetics ◽

Moisture Loss ◽

Effective Moisture Diffusivity ◽

Fluidised Bed ◽

Effective Moisture ◽

Kinetics Of

Konjac glucomannan (KGM) can be obtained from tubers (called corms) of various species within the Amorphophallus genus. Among the most popular species for use in food industry is Buk Nuea Sai (Amorphophallus muelleri), a native species in Thailand. Drying process can be helpful in preserving KGM during long storage periods. However, the existing drying systems are often slow and lead to drying delays and subsequently quality reduction of the dried product. Given the economic importance of KGM, new, more efficient drying systems, have to be developed. The present study focuses on the drying kinetics of konjac dices in a fluidized bed, operating at a constant air velocity of 2.5 m/s and air temperatures of 50, 60, and 70?C. Six empirical mathematical models were selected to describe and compare the drying characteristics of konjac dices subjected to these conditions. The model coefficients were determined by non-linear regression analysis. Among the tested models used to describe the drying kinetics of konjac dices, the two-term model was found as the best one. The moisture loss from the dice was described by the Fick?s diffusion equation, and based on the obtained results the effective moisture diffusivity was estimated, getting a value in the range between 9.60526 ? 10?9 m2/s and 1.2006 ? 10?7 m2/s. The relationship between the temperature and the effective moisture diffusivity was described adequately by means of Arrhenius-type equation. An activation energy value between 8.65 kJ/mol and 61.28 kJ/mol was obtained. The findings allow the successful simulation of konjac dice drying in a fluidized bed between 50 and 70?C, 30-60 mm bed height and 6-15 mm dice thickness.

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