scholarly journals Modeling of mass transfer performance of hot-air drying of sweet potato (Ipomoea Batatas L.) slices

2014 ◽  
Vol 20 (2) ◽  
pp. 171-181 ◽  
Author(s):  
Aishi Zhu ◽  
Feiyan Jiang
Keyword(s):  
Diffusion Coefficient ◽  
Sweet Potato ◽  
Moisture Diffusion ◽  
Drying Process ◽  
Air Velocity ◽  
Potato Slice ◽  
Moisture Diffusion Coefficient ◽  
Hot Air ◽  
Effective Moisture ◽  
Air Dryer

In order to investigate the transfer characteristics of the sweet potato drying process, a laboratory convective hot air dryer was applied to study the influences of drying temperature, hot air velocity and thickness of sweet potato slice on the drying process. The experimental data of moisture ratio of sweet potato slices were used to fit the mathematical models, and the effective diffusion coefficients were calculated. The result showed that temperature, velocity and thickness influenced the drying process significantly. The Logarithmic model showed the best fit to experimental drying data for temperature and the Wang and Singh model were found to be the most satisfactory for velocity and thickness. It was also found that, with the increase of temperature from 60 to 80?C, the effective moisture diffusion coefficient varied from 2.962?10-10 to 4.694?10-10 m2?s-1, and it fitted the Arrhenius equation, the activation energy was 23.29 kJ?mol-1; with the increase of hot air velocity from 0.423 to 1.120 m?s-1, the values of effective moisture diffusion coefficient varied from 2.877?10-10 to 3.760?10-10 m2?s-1; with the increase of thickness of sweet potato slice from 0.002 m to 0.004 m, the values of effective moisture diffusion coefficient varied from 3.887?10-10 to 1.225?10-9 m2?s-1.

scholarly journals RESEARCH OF PLUM DRYING PROCESS

2015 ◽  
Vol 3 ◽  
pp. 494-5 ◽  
Author(s):  
Nurlan Kurmanov ◽  
Azret Shingissov ◽  
Gulzhan Kantureyeva ◽  
Zeinep Nurseitova ◽  
Baurzhan Tolysbaev ◽  
...  
Keyword(s):  
Acid Content ◽  
Ascorbic Acid Content ◽  
Drying Method ◽  
Drying Process ◽  
Air Velocity ◽  
Hot Air ◽  
Sensory Parameters ◽  
Air Dryer ◽  
Kinetics Of

In this study, the drying kinetics of a domestic plum cultivar were examined in a laboratory scale hot-air dryer, SHS-80, at an air velocity of 0.65m s-1 and within the air temperature range of 45 – 75 0С. It was found that the whole fruit dried the best. Also, the study  assessed the influence of the drying method on the quality of the domestic plum cultivar. Dried fruits were assessed for sensory parameters and ascorbic acid content. Studies have shown thatthe proposed method of drying, yields a higher absorbic acid content for the dried product  than the conventional approach.

scholarly journals Moisture diffusion coefficient estimation in peas drying by means of a modified Hawlader and Uddin method

2018 ◽  
Author(s):  
Carlos Martínez-Vera ◽  
Mario Vizcarra-Mendoza
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Equation ◽  
Diffusion Coefficients ◽  
Moisture Diffusion ◽  
Moisture Diffusivity ◽  
Second Step ◽  
Drying Process ◽  
Moisture Diffusion Coefficient ◽  
Coefficient Estimation ◽  
Constant Diffusion

The aim of the present work is to determine the moisture diffusion coefficient in peas applying, in a first step, a methodology previously published in the literature by Uddin et al.[1] for determining constant diffusion coefficients taking in account the volume reduction associated to the drying process. Then, in a second step, refine it by means of an optimization step. The optimization step is justified because the methodology of Uddin et al. is based in a solution of the diffusion equation that is not mathematically valid for the drying-shrinking problem. Keywords: : moisture diffusivity; drying-shrinking; peas drying 

scholarly journals Moisture transport through non-porous hydrophilic membranes used in protective clothing

2013 ◽  
Vol 17 (5) ◽  
pp. 1293-1298 ◽  
Author(s):  
Fang-Long Zhu ◽  
Yu Zhou ◽  
Jian-Xin He
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Model ◽  
Transfer Process ◽  
Moisture Transfer ◽  
Effective Diffusion ◽  
Moisture Diffusion ◽  
Mass Transfer Process ◽  
Transfer Resistance ◽  
Moisture Diffusion Coefficient ◽  
Effective Moisture

The three-step upright cup method was employed to determine the total moisture transfer resistance and the two air layer resistances on both sides of the membrane. The effective moisture diffusion coefficient in air layer between the membrane and water surface was determined by the regressive method, and the effective moisture diffusion coefficient of membrane was calculated. Experiments were conducted on a non-porous hydrophilic thermoplastic polyester elastomer membrane. The moisture transfer process through the membrane was modeled by using the solution-diffusion model. The effects of membrane microstructure on membrane permeation were analyzed based on the solution-diffusion model and experimental data. The results show that the effective diffusion coefficient can be used to evaluate the mass transfer process through the non-porous hydrophilic thermoplastic polyester elastomer membrane.

scholarly journals Evaluation of the Mass Diffusion Coefficient and Mass Biot Number Using a Nondominated Sorting Genetic Algorithm

Symmetry ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 260 ◽  
Author(s):  
Radosław Winiczenko ◽  
Krzysztof Górnicki ◽  
Agnieszka Kaleta
Keyword(s):  
Genetic Algorithm ◽  
Diffusion Coefficient ◽  
Biot Number ◽  
Moisture Diffusion ◽  
Absolute Error ◽  
Mass Diffusion ◽  
Precise Determination ◽  
Nsga Ii ◽  
Moisture Diffusion Coefficient ◽  
Nondominated Sorting

A precise determination of the mass diffusion coefficient and the mass Biot number is indispensable for deeper mass transfer analysis that can enable finding optimum conditions for conducting a considered process. The aim of the article is to estimate the mass diffusion coefficient and the mass Biot number by applying nondominated sorting genetic algorithm (NSGA) II genetic algorithms. The method is used in drying. The maximization of coefficient of correlation (R) and simultaneous minimization of mean absolute error (MAE) and root mean square error (RMSE) between the model and experimental data were taken into account. The Biot number and moisture diffusion coefficient can be determined using the following equations: Bi = 0.7647141 + 10.1689977s − 0.003400086T + 948.715758s2 + 0.000024316T2 − 0.12478256sT, D = 1.27547936∙10−7 − 2.3808∙10−5s − 5.08365633∙10−9T + 0.0030005179s2 + 4.266495∙10−11T2 + 8.33633∙10−7sT or Bi = 0.764714 + 10.1689091s − 0.003400089T + 948.715738s2 + 0.000024316T2 − 0.12478252sT, D = 1.27547948∙10−7 − 2.3806∙10−5s − 5.08365753∙10−9T + 0.0030005175s2 + 4.266493∙10−11T2 + 8.336334∙10−7sT. The results of statistical analysis for the Biot number and moisture diffusion coefficient equations were as follows: R = 0.9905672, MAE = 0.0406375, RMSE = 0.050252 and R = 0.9905611, MAE = 0.0406403 and RMSE = 0.050273, respectively.

scholarly journals Influence of Different Hot Air Drying Temperatures on Drying Kinetics, Shrinkage, and Colour of Persimmon Slices

Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 101 ◽  
Author(s):  
Senadeera ◽  
Adiletta ◽  
Önal ◽  
Di Matteo ◽  
Russo
Keyword(s):  
Moisture Content ◽  
Quadratic Model ◽  
Drying Process ◽  
Air Velocity ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Drying Characteristics ◽  
Drying Temperature ◽  
Hot Air

Drying characteristics of persimmon, cv. “Rojo Brillante”, slabs were experimentally determined in a hot air convective drier at drying temperatures of 45, 50, 55, 60, and 65 °C at a fixed air velocity of 2.3 m/s. It was observed that the drying temperature affected the drying time, shrinkage, and colour. Four empirical mathematical models namely, Enderson and Pabis, Page, Logarithmic, and Two term, were evaluated in order to deeply understand the drying process (moisture ratio). The Page model described the best representation of the experimental drying data at all investigated temperatures (45, 50, 55, 60, 65 °C). According to the evaluation of the shrinkage models, the Quadratic model provided the best representation of the volumetric shrinkage of persimmons as a function of moisture content. Overall, higher drying temperature (65 °C) improved the colour retention of dried persimmon slabs.

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