Drying of a Low Porosity Product (Carrot) as Affected by Power Ultrasound

2008 ◽  
Vol 273-276 ◽  
pp. 764-769 ◽  
Author(s):  
J.V. García-Pérez ◽  
J.A. Cárcel ◽  
J. Benedito ◽  
E. Riera ◽  
A. Mulet
Keyword(s):  
Mass Transfer ◽  
Electric Power ◽  
Ultrasonic Transducer ◽  
Energy Levels ◽  
Drying Kinetics ◽  
Acoustic Energy ◽  
Convective Drying ◽  
Power Ultrasound ◽  
Kinetics Of ◽  
Low Porosity

The main aim of this work was to assess the influence of power ultrasound on mass transfer process during convective drying of a low porosity product submitted to different acoustic energy levels. Drying kinetics of carrot cubes (side 8.5 mm) were carried out at 40 °C and 1 m/s applying different electric power levels to the ultrasonic transducer: 0, 10, 20, 30, 40, 50, 60, 70, 80 and 90 W. Drying kinetics were modelled considering the diffusion theory. From the results, a significant (p<0.05) influence of power ultrasound application on drying kinetics of carrot cubes was found. Drying rate increased as the electric power applied got higher. The influence was only observed above an acoustic energy threshold, which corresponded to an electric power applied to the transducer of 20-30 W. From this threshold, a linear relationship was found between the average effective moisture diffusivity or the mass transfer coefficient and the electric power applied to the transducer.

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.

Convective Drying Kinetics of Polymer Strip Films Loaded with a BCS Class II Drug

2019 ◽  
Vol 20 (2) ◽  
Author(s):  
A. T. Naseri ◽  
E. Cetindag ◽  
J. Forte ◽  
E. Bilgili ◽  
Rajesh N. Davé
Keyword(s):  
Class Ii ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Bcs Class Ii ◽  
Kinetics Of

Experimental Evaluation and Kinetic Analysis of Direct-Contact Ultrasonic Fabric Drying Process

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Chang Peng ◽  
Saeed Moghaddam
Keyword(s):  
Direct Contact ◽  
Ultrasonic Transducer ◽  
Gaussian Model ◽  
Weibull Model ◽  
Drying Kinetics ◽  
Energy Prices ◽  
Drying Process ◽  
Liquid Form ◽  
Drying Time ◽  
Kinetics Of

Abstract Over the past two decades, due to the rising energy prices and growing awareness about climate change, significant efforts have been devoted to reducing the energy consumption of various home appliances. However, the energy efficiency of clothes dryers has little improvement. Recent innovations in the direct-contact ultrasonic fabric drying technique offer new opportunities for energy saving. In this technique, high-frequency mechanical vibrations generated by the ultrasonic transducer are utilized to atomize water from a fabric in the liquid form, which demonstrates great potential for reducing energy use and drying time of the fabric drying process. Here, for the first time, fabric drying kinetics under different direct-contact ultrasonic drying conditions were investigated experimentally and analytically. The drying processes of four kinds of fabrics were experimentally tested under different ultrasonic transducer vibration frequency (115, 135, and 155 kHz) and input power (1.2, 2.5, and 4.4 W) conditions. According to the experimental data, five different kinds of models were applied to quantify the drying kinetics of fabrics during direct-contact ultrasonic drying. The models not only incorporated the transducer parameters but also the parameters related to the nature of fabric. Our evaluation results of model prediction performance demonstrated that the two empirical models, i.e., the Weibull model and the Gaussian model, were superior to the three semi-theoretical models for anticipating the drying kinetics of fabrics under direct-contact ultrasonic drying. Furthermore, the Weibull model is more suitable for practical energy-efficient direct-contact ultrasonic fabric drying applications compared with the Gaussian model.

Influence of Osmotic Pre-treatment on Convective Drying Kinetics of Figs

2013 ◽  
Vol 9 (2) ◽  
pp. 187-196 ◽  
Author(s):  
Juliana M. Silva ◽  
Muriel G. Cantu ◽  
Vera Rodrigues ◽  
Marcio A. Mazutti
Keyword(s):  
Experimental Data ◽  
Moisture Content ◽  
Osmotic Dehydration ◽  
Sucrose Concentration ◽  
Drying Kinetics ◽  
Soluble Solids ◽  
Convective Drying ◽  
Final Time ◽  
Osmotic Treatment ◽  
Kinetics Of

AbstractThis work evaluated the effects of osmotic dehydration on convective drying kinetics of figs. It used the experimental design methodology to evaluate the influence of sucrose concentration, temperature and time on the amount of total soluble solids (TSS) and moisture content of the figs. After the osmotic dehydration, it evaluated the convective drying kinetics at temperatures from 55 to 75°C. A mathematical model was employed to fit the experimental data. From the experimental data of the osmotic dehydration, it was seen that the moisture content of the figs after the treatment was closely related to the amount of TSS of the figs. Low moisture content and high TSS content were obtained for a narrow range of independent variables comprised between 55–60°C, 55–63 wt% and 260–280 min for temperature, sucrose concentration and exposure time, respectively. In the convective drying kinetics of the figs, there were no verified significant differences in the final time of drying of non-treated and osmotically dehydrated figs. However, the shrinkage was considerably reduced in the osmotically treated figs. The use of osmotic treatment enables the obtainment of figs softer than the simple use of convective drying without changing the final time of drying.

Effect of Air Temperature on Convective Drying Assisted by High Power Ultrasound

2006 ◽  
Vol 258-260 ◽  
pp. 563-574 ◽  
Author(s):  
J.V. García-Pérez ◽  
Carmen Rosselló ◽  
J.A. Cárcel ◽  
Susana De la Fuente ◽  
A. Mulet
Keyword(s):  
Mass Transfer ◽  
Air Temperature ◽  
Drying Kinetics ◽  
Drying Rate ◽  
External Resistance ◽  
Experimental Conditions ◽  
Power Ultrasound ◽  
Effective Moisture ◽  
High Power Ultrasound ◽  
Er Model

Drying kinetics of carrot cubes were carried out at 1 m/s air velocity at different air drying temperatures (30, 40, 50, 60 and 70±0.1 °C) (AIR experiments), and also at the same experimental conditions but applying high power ultrasound (US experiments). Two kind of diffusion models were used to simulate the drying kinetics, according to external resistance to mass transfer being considered (ER model) or neglected (NER model) for solving the diffusion equation. Diffusion ER model was solved using a finite difference method. Drying rate increased as air temperature was higher. Ultrasound also increased drying rate at the different temperatures, but the improvement on drying rate decreased at high temperatures, and almost disappeared at 70 °C. Effective moisture diffusivities only showed an Arrhenius type relationship with temperature for AIR experiments. The NER diffusion model was not accurate to simulate the drying kinetics at any experimental conditions tested. However, diffusion ER model provided a high closeness between experimental and calculated drying data (VAR>99.80). Through the parameters identified of the ER diffusion model, effective moisture diffusivity and mass transfer coefficient, the influence of the power ultrasound application on internal and external resistance to mass transfer was shown to be significant (p<0.05).

Convective Drying Kinetics of Fresh Beef: An Experimental and Modeling Approach

2015 ◽  
Vol 39 (6) ◽  
pp. 2581-2595 ◽  
Author(s):  
Tom Ahmat ◽  
Mahamat Barka ◽  
Aworou-Waste Aregba ◽  
Denis Bruneau
Keyword(s):  
Drying Kinetics ◽  
Convective Drying ◽  
Modeling Approach ◽  
Kinetics Of

Analysis of Freeze-Drying and Rehydration of Açai (Euterpe oleracea Martius)

2015 ◽  
Vol 365 ◽  
pp. 11-16
Author(s):  
R.J. Brandão ◽  
M.M. Prado ◽  
L.G. Marques
Keyword(s):  
Mass Transfer ◽  
Energy Demand ◽  
Freeze Drying ◽  
Moisture Diffusion ◽  
Euterpe Oleracea ◽  
Power Ultrasound ◽  
Ultrasound Waves ◽  
Freeze Dried ◽  
Peleg’S Equation ◽  
Kinetics Of

The freeze-drying rate is essentially low, since it is controlled by internal moisture diffusion. In addition, the application of vacuum and low temperature during the process presents a higher energy demand. Therefore, the search for new strategies to improve water mobility during freeze-drying constitutes a topic of relevant research. The aim of this work was to evaluate the use of power ultrasound to improve freeze-drying characteristics of açai, quantifying the influence of the applied power on both the drying and rehydration kinetics of the material. Açai (Euterpe oleracea Martius) samples were sonicated with two different frequency levels, 20 kHz and 40 kHz, and two sonication times, 3 min and 10 min. Page’s equation considering internal and external resistances to mass transfer provided a good fit of freeze-drying kinetics, while the Peleg’s equation was found to be suitable for describing the rehydration kinetics of freeze-dried açai. Pretreatment of açai with ultrasound waves was not effective. Ultrasound-induced structural disruption in the açai skin hindered the mass transfer during both freeze-drying and rehydration processes.

Ultrasonic Convective Drying Kinetics of Clipfish During the Initial Drying Period

2013 ◽  
Vol 31 (11) ◽  
pp. 1307-1316 ◽  
Author(s):  
Michael Bantle ◽  
Joachim Hanssler
Keyword(s):  
Drying Kinetics ◽  
Convective Drying ◽  
Kinetics Of
Sign in / Sign up

Export Citation Format

Share Document