Drying Kinetic Simulation of Clay Tiles Made from the Raw Material Having Less Clay Fraction

2014 ◽  
Vol 1036 ◽  
pp. 3-8
Author(s):  
Miloš Vasić ◽  
Zagorka Radojević
Keyword(s):  
Clay Fraction ◽  
Effective Diffusivity ◽  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Diffusivity Coefficient ◽  
Moisture Movement ◽  
Effective Moisture ◽  
Drying Kinetic ◽  
Clay Tiles

In order to describe the internal moisture rate and to take all different mechanisms of moisture movement into account, it is suitable to use effective diffusivity as a measure of moisture rate, irrespectively of the mechanisms really involved. This means that all different mechanisms and driving forces for internal moisture transport are lumped together and introduced into effective moisture diffusivity. Hence, diffusion equations are retained and reused with the effective diffusivity coefficient as a measuring parameter of internal moisture ratio. In our previous studies we have presented the calculation method which assumed constant diffusivity. The next goal was to estimate effective diffusivity at various moisture contents, in a real case of non-linear drying curves, and to predict drying kinetic. In our last study we have developed a model for determination of the variable effective diffusivity and identification of the exact transition points between possible drying mechanisms. In this paper we have tried to develop more accurate tool for determination of time dependent effective moisture diffusivity. An analytical model and computing procedure were developed to evaluate mass transfer properties and describe drying kinetic of clay tiles having less clay fraction. The proposed procedure was validated with experimental drying data. Presented results have demonstrated that the proposed dying model can be applied for the accurate description of experimental drying kinetics and a reliable estimation of effective diffusivity.

Drying Simulation of Shrinkable Clay Tiles Using Variable Diffusivity Model

2013 ◽  
Vol 837 ◽  
pp. 506-510 ◽  
Author(s):  
Miloš Vasić ◽  
Zagorka Radojević
Keyword(s):  
Moisture Diffusivity ◽  
Time Dependent ◽  
Effective Moisture Diffusivity ◽  
Experimental Investigations ◽  
Variable Diffusivity ◽  
Effective Moisture ◽  
Drying Kinetic ◽  
Constant Diffusivity ◽  
Drying Model ◽  
Clay Tiles

This paper represents the upgrade of our previous study in which we have presented a model for simulation of the drying kinetic and estimation of the effective moisture diffusivity of clay tiles using a constant diffusivity model. The main objective of this study is to determine the time - dependent effective moisture diffusivity of shrinkable clay tiles. Experimental investigations were carried out, on clay tiles, in a laboratory recirculation dryer in which drying parameters (humidity, temperature, and velocity) could be programmed, controlled and monitored during drying. Results presented in this study have shown that the proposed drying model describes and correlates accurately drying kinetics and gives a reliably estimation of the time - dependent effective moisture diffusivity.

scholarly journals Optimization and Prediction of the Drying and Quality of Turnip Slices by Convective-Infrared Dryer under Various Pretreatments by RSM and ANFIS Methods

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 284
Author(s):  
Ebrahim Taghinezhad ◽  
Mohammad Kaveh ◽  
Antoni Szumny
Keyword(s):  
Energy Efficiency ◽  
Color Difference ◽  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Diffusivity Coefficient ◽  
Drying Process ◽  
Anfis Model ◽  
Drying Time ◽  
Effective Moisture ◽  
Response Variables

Drying can prolong the shelf life of a product by reducing microbial activities while facilitating its transportation and storage by decreasing the product weight and volume. The quality factors of the drying process are among the important issues in the drying of food and agricultural products. In this study, the effects of several independent variables such as the temperature of the drying air (50, 60, and 70 °C) and the thickness of the samples (2, 4, and 6 mm) were studied on the response variables including the quality indices (color difference and shrinkage) and drying factors (drying time, effective moisture diffusivity coefficient, specific energy consumption (SEC), energy efficiency and dryer efficiency) of the turnip slices dried by a hybrid convective-infrared (HCIR) dryer. Before drying, the samples were treated by three pretreatments: microwave (360 W for 2.5 min), ultrasonic (at 30 °C for 10 min) and blanching (at 90 °C for 2 min). The statistical analyses of the data and optimization of the drying process were achieved by the response surface method (RSM) and the response variables were predicted by the adaptive neuro-fuzzy inference system (ANFIS) model. The results indicated that an increase in the dryer temperature and a decline in the thickness of the sample can enhance the evaporation rate of the samples which will decrease the drying time (40–20 min), SEC (from 168.98 to 21.57 MJ/kg), color difference (from 50.59 to 15.38) and shrinkage (from 67.84% to 24.28%) while increasing the effective moisture diffusivity coefficient (from 1.007 × 10−9 to 8.11 × 10−9 m2/s), energy efficiency (from 0.89% to 15.23%) and dryer efficiency (from 2.11% to 21.2%). Compared to ultrasonic and blanching, microwave pretreatment increased the energy and drying efficiency; while the variations in the color and shrinkage were the lowest in the ultrasonic pretreatment. The optimal condition involved the temperature of 70 °C and sample thickness of 2 mm with the desirability above 0.89. The ANFIS model also managed to predict the response variables with R2 > 0.96.

Non-isothermal drying of bio-wastes: Kinetic analysis and determination of effective moisture diffusivity

2020 ◽  
Vol 262 ◽  
pp. 110348 ◽  
Author(s):  
Yanina Baldán ◽  
Anabel Fernandez ◽  
Andrés Reyes Urrutia ◽  
María Paula Fabani ◽  
Rosa Rodriguez ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Effective Moisture ◽  
Isothermal Drying

A Method of Determination of Concentration Dependent Effective Moisture Diffusivity

1995 ◽  
Vol 13 (5-7) ◽  
pp. 1477-1488 ◽  
Author(s):  
G.S.V. Raghavan ◽  
T.N. Tulasidas ◽  
S.S. Sablani ◽  
H.S. Ramaswamy
Keyword(s):  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Effective Moisture ◽  
Method Of Determination

scholarly journals Mathematical modeling and effect of blanching pretreatment on the drying kinetics of Chinese yam (Dioscorea opposita)

2015 ◽  
Vol 21 (4) ◽  
pp. 511-518 ◽  
Author(s):  
Sheng Fang ◽  
Li-Ping Wang ◽  
Ting Wu
Keyword(s):  
Model Performance ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Effective Moisture Diffusivity ◽  
Diffusivity Coefficient ◽  
Drying Time ◽  
Chinese Yam ◽  
Effective Moisture ◽  
Dioscorea Opposita ◽  
Kinetics Of

The influences of blanching pretreatment on the drying kinetics of Chinese yam (Dioscorea opposita) slices were investigated. Drying experiments were carried out at 60, 70, 80 and 90?C. Six thin layer models were evaluated and the determination of coefficient (R2), chi-square (?2), root means square error (RMSE) were used to analysis the model performance for both raw and blanched samples. The Wang and Singh model gave best results with R2 of 0.9987 and RMSE of 0.0136 for raw yam slices, and R2 of 0.9989 and RMSE of 0.0119 for blanched samples. The effective moisture diffusivity coefficient Deff varied in the range of 0.7295?10-9 to 2.4087?10-9m2 s-1 for raw slices, and 1.3748?10-9 to 3.8524?10-9m2 s-1 for the blanche dones. The activation energy of yam slices drying were 41.149 and 33.499 kJ mol-1 for raw and blanched yam slices, respectively. Results show that blanching pretreatment can reduce the total drying time and improve the effective moisture diffusivity compared with the raw samples.

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