Estimation of coal moisture content in convective drying process using ANFIS

2016 ◽  
Vol 147 ◽  
pp. 12-17 ◽  
Author(s):  
Saban Pusat ◽  
Mustafa Tahir Akkoyunlu ◽  
Engin Pekel ◽  
Mehmet Cabir Akkoyunlu ◽  
Coşkun Özkan ◽  
...  
2020 ◽  
Vol 175 ◽  
pp. 05021
Author(s):  
Sergey Antipov ◽  
Andrey Klyuchnikov ◽  
Dmitry Kazartsev

At the present time the maim quantity of free-running food products, including grains, are dried in units with convective method of heat input. To intensify convective drying, general attention is paid to improving the method of moving and mixing the product with drying agent, to guarantee fast and quality drying. The use of high and super-high frequency allows can significantly intensify the drying processes, because the phenomenon of super-high frequencies energy into heat conversion throughout the processed material volume contributes to the most uniform heating of the product, compared to other heat input methods. The optimal solution for drying free-running food products is a combination of convective and high-frequency heat input methods. This combination allows controlling gradients of moisture content and temperature, changing its directions, which significantly affects quality of the resulting dry product. In this regard, combined approach to drying process modeling is of practical interest: on the one hand, there are used analytical solutions, based on physical laws application or phenomenological equations, and, on the other hand, experimentally established a relationship between temperature and moisture content of media, which is considered as a heat and mass transfer characteristic for each material.


Author(s):  
Karine Machry ◽  
Marcílio Machado Morais ◽  
Gabriela Silveira da Rosa

Jaboticaba (Plinia cauliflora) is a Brazilian fruit with a high content of anthocyanins compounds. Peel corresponds to 30 % of the fruit weight and it is considerated a residue since just the pulp is used. The aim of this work was to analyze the convective drying process of the jaboticaba peels. Moisture content of dried peels showed a range of 7.17 to 13.26 (% w.b.). The results also reported that jaboticaba peels have high anthocyanins content (fresh: 1162.99 ± 41.35 mg/100g d.b) and it was possible to maintain these compounds even after the drying process (1052 to 1270 mg/100g d.b).Keywords: jaboticaba; peel; drying; residue; anthocyanins.


Author(s):  
Rym Mbarek ◽  
Daoued Mihoubi

The evolution of physical properties (shrinkage, density and porosity) of cylindrical shaped apple samples (Golden Delicious) during convective drying was investigated. For this purpose, the weight and the dimensions (diameter, height) of apple samples were monitoring at regular time intervals of the drying process. A constant drying rate period was not detected although considering the reduction of the exchange surface area. Apple exhibited a clear anisotropy behavior of the shrinkage coefficients. The volume shrinkage of apple samples showed a linear relationship with moisture content (R2 = 0.996). A theoretical relation between the surface ratio and the volume ratio was determined (R2 = 0.956). During drying process, the apparent density of apples decreased with decrease in moisture content following a second-degree polynomial curve (R2 = 0.991), whereas the true density aggrandized with removal of water. The porosity of apple samples was showed to increase as drying progressed. At the starting of the drying process, the porosity changes resulted from the reduction of the total volume. Then, the porosity changes during drying were found to be a consequence of a loss of water and a simultaneous reduction of gaseous volume.


2020 ◽  
Vol 400 ◽  
pp. 51-56
Author(s):  
Francisca Valdeiza de Souza Tavares ◽  
Atacy Maciel de Melo Cavalcante ◽  
Maria José de Figueiredo ◽  
Anderson Ferreira Vilela ◽  
Ana Raquel Carmo de Lima ◽  
...  

This paper aims to study convective drying of industrial hollow bricks in a tunnel dryer. A transient mathematical model based on the heat and mass conservation equations applied to the air and brick was derived and the numerical solution (finite-volume method) of the governing equations is presented. Predicted and experimental data of the average moisture content and the temperature of the product during the drying process are compared and a good concordance was verified. Numerical results inside the bed confirm an almost null difference between the moisture content along the process. Similar behavior was verified to the product temperature. These results confirm an efficient drying process.


Author(s):  
Marina Sergeevna Maklusova ◽  
Maria Konstantinovna Kosheleva ◽  
Olga Roaldovna Dornyak

The object of research is a fiber-forming polymer - polycaproamide. The process of drying of polycaproamide granules, after aqueous extraction of low-molecular compounds from them, is an important stage of producing of polyamide fiber nylon and largely determines the quality of the target product. To obtain a high-quality fiber, the drying of the granules should provide a sufficiently high degree of its dehydration. The average final moisture content of the material should be no more than 0.1%. With a low moisture content, the drying process slows down, so the calculation of the kinetics of dewatering of granules can not be carried out using a constant effective mass-transfer coefficient (moisture diffusion). In this paper we present a calculation technique for determining two local parameters of mass transfer: the water diffusion coefficient in polycaproamide (as a liquid) and the so-called criterion for phase transitions, which depend on the moisture content of the material and are determined by its sorption properties. The report presents the results of numerical calculations illustrating the development of two-dimensional fields of moisture content, temperature, pressure and vapor concentration in the vapor-gas phase for cylindrical granules in convective drying. To describe the processes of heat and mass transfer during the drying of granules, a nonstationary nonlinear 2D model is used that includes transport equations averaged over the microvolume of the material: the liquid phase transfer equation; heat equation; equation for vapor-gas phase pressure; equation for the concentration of the vapor component. The nonstationary nonlinear conjugate mathematical model is studied numerically. A feature of the presented model is the possibility of an analytical calculation of the local mass transfer coefficients of a liquid, taking into account the sorption properties of the material, the permeability coefficient and the local values ​​of humidity and temperature. Determination of the local coefficients of moisture transfer is carried out on the basis of the formulas obtained in the analysis of a more general mathematical model of heat and mass transfer carried out based on the mechanics of multiphase systems developed in the works of R.I. Nigmatulin, and S. Whitaker. The structure of the samples was investigated by three independent methods in order to obtain the most complete idea of ​​it and to compare the obtained characteristics. The isotherms of the sorption of polycaproamide were obtained experimentally on a vacuum sorption plant with Mac-Ben-Bakr weights. Comparison of the results of mathematical modeling of heat and mass transfer in the granule and data of the laboratory experiment on the kinetics of polycaproamide granule drying showed good agreement between the calculated and experimental data. The constructed mathematical model allows to form energy-efficient resource-saving regimes for drying granules of polycaproamide.Keywords: convective drying, mathematical modeling, polycaproamide.


2018 ◽  
Vol 24 (5) ◽  
pp. 382-393 ◽  
Author(s):  
Monia Jebri ◽  
José Tarrazó ◽  
José Bon ◽  
Hélène Desmorieux ◽  
Mehrez Romdhane

The current study deals with an innovation in the hot air convective drying process consisting of the application of two consecutive drying steps. Temperatures ranging between 60 and 80 ℃ for times between 200 and 600 s were applied for the first stage, and from 40 to 80 ℃ for the second stage. Salvia officinalis, an aromatic, medicinal Mediterranean plant with remarkable antioxidant properties, was selected for this study. A management of the process regarding the antioxidant capacity of S. officinalis extracts and energy consumption was carried out: (i) artificial neural networks were applied to model the evolution of the antioxidant capacity and moisture content of the product in the drying process; (ii) a genetic algorithm and a multiobjective genetic algorithm were selected to optimize the drying process, considering the antioxidant capacity and/or the energy consumption in the objective function. The results showed that the optimum values depended, logically, on the controllable variables values (hot air temperatures and drying times), but also on the uncontrollable variable values (room air temperature and relative humidity and the product’s initial mass and moisture content).


Author(s):  
A. I. Ol’shanskii ◽  
S. V. Zhernosek ◽  
A. M. Gusarov

New ways of experimental data processing by generalized complex variables that are characteristic of the drying process are presented. The authors presented the results of a study of heat and moisture exchange in the convective drying of thin flat moist capillary-porous materials. As a result of the processing of the experimental data, equations were obtained for determining the densities of heat fluxes, average integral temperatures, drying time and moisture evaporation rate in the second drying period. The relationship between the densities of heat fluxes in the first and second periods and the temperature change in the second period is revealed. The dependence for calculating the temperature of the material in the period of the falling drying rate taking into account the heat that is expended to heat the wet body is presented. The equations for determining the temperature in the second period by the temperature coefficient of drying, the rate of heating of the wet material and the rate of heating of the wet body are presented as well. An equation for determining the drying time by the value of the rate of loss of moisture content of the material is given. A mathematical expression for calculating the intensity of moisture evaporation in the first and second drying periods depending on the ratio of moisture content in the first period and the current in the second moisture content one is set. The conditions of a regular regime for heat and moisture exchange for a second drying period are adduced. The authors consider the possibility of determining the rate of heating of wet material by the heating rate using the graphical differentiation of the temperature function, which is described by the curve, as a function of time in the second drying period. The problems of using the methods of the theory of the regular regime for heating wet bodies during the investigation of the drying process are considered. The formulas for determining the rate of heating of the body and the rate of loss of moisture content are given. The accuracy of the experimental data processing and the reliability of the experimental equations obtained for all the materials under study are verified. As a result of the research, all the basic kinetic characteristics necessary for the calculation of heat and moisture exchange in the drying process have been determined.


2012 ◽  
Vol 2 (1) ◽  
pp. 14-20
Author(s):  
Yuwana Yuwana

Experiment on catfish drying employing ‘Teko Bersayap’ solar dryer was conducted. The result of the experiment indicated that the dryer was able to increase ambient temperature up to 44% and decrease ambient relative humidity up to 103%. Fish drying process followed equations : KAu = 74,94 e-0,03t for unsplitted fish and KAb = 79,25 e-0,09t for splitted fish, where KAu = moisture content of unsplitted fish (%), KAb = moisture content of splitted fish (%), t = drying time. Drying of unsplitted fish finished in 43.995 hours while drying of split fish completed in 15.29 hours. Splitting the fish increased 2,877 times drying rate.


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