scholarly journals Modeling of heat and mass transfer in the process of drying of colloid capillary - porous materials

2019 ◽  
pp. 7-14 ◽  
Author(s):  
Zh.O. Petrova ◽  
B.V. Davydenko ◽  
K.S. Slobodianiuk
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Porous Materials ◽  
Heat And Mass Transfer ◽  
Heat Mass Transfer ◽  
Nonlinear Differential Equations ◽  
Technical Problem ◽  
Experimental Studies ◽  
Drying Process ◽  
The Creation

The process of drying is an energy-consuming process, therefore, in order to optimize these energy costs during drying and to choose the rational structural and regime parameters of the equipment intended for this process, it is necessary to carry out a calculation analysis of heat and mass transfer on the basis of adequate mathematical models. The study of various mechanisms of diffusion in capillary - porous materials has become the basis for the creation of a mathematical model of heat - mass transfer and for the formulation of a corresponding system of nonlinear differential equations. Using mathematical model of heat-mass transfer A.V. Lykova constructed an appropriate numerical algorithm for modeling this process, numerical studies of the convection drying process of colloidal capillary - porous materials (KKPM) have been performed. The boundary conditions on the contact surface of the material in the drying chamber with the heat carrier flow are formulated. Based on the numerical solution of the system of one-dimensional heat and mass transfer equations in the material, depending on the time of its specific moisture content and temperature, as well as other characteristics of the convection drying process, the dependence was obtained. The estimated results are compared with the results of experimental studies. From the results of the comparison, it follows that the calculated model on the basis of the proposed system of equations satisfactorily describes the process of mass transfer in colloidal capillary - porous materials and can be used to approximate the characteristics of the drying process of colloidal capillary - porous materials, in particular the time required for drying the material. Numerical modeling of heat and mass transfer processes in colloid capillary and porous materials helps to solve an important scientific and technical problem, which is connected with the creation of software and hardware complexes, automated systems of scientific researches of energy-saving heat-technological processes of drying of materials with the provision of necessary quality indicators. Having analyzed the literature data concerning the existing developed mathematical modeling of colloidal capillary-porous materials, it has been established that this direction has a limited amount of information and therefore requires in-depth study and is an actual direction of research.

scholarly journals RESEARCH OF HEAT AND MASS TRANSFER DURING CONVECTIVE DRYING OF COLLOID CAPILLARY-POROUS MATERIALS

2020 ◽  
Author(s):  
Kateryna Slobodianiuk ◽  
◽  
Kateryna Samoilenko ◽  
Keyword(s):  
Mass Transfer ◽  
Porous Materials ◽  
Heat And Mass Transfer ◽  
Raw Materials ◽  
Biochemical Properties ◽  
The Body ◽  
Biologically Active ◽  
Convective Drying ◽  
Drying Process ◽  
Vegetable Raw Materials

The article presents a reasonable analysis and relevance of the study of the drying process of vegetable raw materials (colloidal capillary-porous materials). Drying is an energy-intensive industrial process that is defined from a technological point of view: on the one hand by heat and moisture exchange between the body surface and the environment, on the other hand by heating the body and transferring moisture inside it due to the form of moisture. One of the most effective ways to increase the shelf life of food is to dry it to equilibrium humidity. Very important are the technological parameters of the drying regimes, which, when used rationally, are able to preserve the biochemical properties and nutrients of the raw material at a high level in the obtained dry product. The study of dehydration of vegetable raw materials is widely practiced around the world, especially in countries such as Germany, France, USA, Argentina, Hungary, Brazil, Poland, Korea, China, Malaysia. However, the obtained processed products lose their biologically active components and nutrients, and the processing process is energy consuming. Therefore, the problem is relevant and needs an effective solution. In this paper, the kinetics of the drying process, thermogravimetric studies and a mathematical model for colloidal capillary-porous materials of plant origin were analyzed. According to the results of the highlighted research, the process of convective drying of colloidal capillary-porous materials was intensified above 21% due to the use of innovative step regimes. The developed beet-rhubarb composition is a colloidal capillary-porous material that stabilizes and protects at the biochemical level betanin of the beet from the effects of temperature during convective drying, has in comparison with the components of the composition lower heat of dehydration and increased thermal-stability. Prolonged high-temperature exposure causes instant complete destruction of sugars, proteins and other nutrients components. Derivatographic studies have confirmed that the use of the temperature range of 100 ° C in a stepwise mode of 100/60 ° C for the developed soybean-spinach composition is safe for biologically active substances and it is justified by experimental temperature curves. Numerical modeling of heat and mass transfer during convective drying of crushed beets and crushed soybeans using the known model by A.V. Lykov satisfactorily describes the process and can be used to model the convection drying of colloidal capillary-porous materials.

scholarly journals System Model of Heat and Mass Transfer Process for Mobile Solvent Vapor Phase Drying Equipment

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Shiwei Zhang ◽  
Yufang Zhu ◽  
Baozhen Qiao ◽  
Zhijun Zhang
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Technological Process ◽  
Vapor Phase ◽  
Power Transformer ◽  
Water Yield ◽  
Drying Process ◽  
Solvent Vapor ◽  
Theoretical Simulation

The solvent vapor phase drying process is one of the most important processes during the production and maintenance for large oil-immersed power transformer. In this paper, the working principle, system composition, and technological process of mobile solvent vapor phase drying (MVPD) equipment for transformer are introduced in detail. On the basis of necessary simplification and assumption for MVPD equipment and process, a heat and mass transfer mathematical model including 40 mathematical equations is established, which represents completely thermodynamics laws of phase change and transport process of solvent, water, and air in MVPD technological processes and describes in detail the quantitative relationship among important physical quantities such as temperature, pressure, and flux in key equipment units and process. Taking a practical field drying process of 500 KV/750 MVA power transformer as an example, the simulation calculation of a complete technological process is carried out by programming with MATLAB software and some relation curves of key process parameters changing with time are obtained such as body temperature, tank pressure, and water yield. The change trend of theoretical simulation results is very consistent with the actual production record data which verifies the correctness of mathematical model established.

scholarly journals Mathematical model of vacuum freeze-drying in the secondary drying

2007 ◽  
Vol 3 (2) ◽  
pp. 192-196
Author(s):  
Hua Li ◽  
Lihua Li ◽  
Xingli Jiao ◽  
Xueli Qin
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Transfer Process ◽  
Present Status ◽  
Freeze Drying ◽  
Mass Transfer Process ◽  
Drying Process ◽  
Secondary Drying ◽  
At Home

The freeze-drying process is a complex heat and mass transfer process virtually. The drying process of freeze-drying is not only the key stage which decides the success of freeze-drying, but also the most difficult stage to control. There are lots of papers about heat and mass transfer in vacuum freeze drying at home and abroad. The present status of research on heat and mass transfer during vacuum freeze drying in the secondary drying is summed up and analyzed, and the trend of research in this field is discussed in this paper.

Mathematical modeling of timber elastic-viscous-plastic deformation in the wood drying process

10.12737/4522 ◽  
2014 ◽  
Vol 4 (2) ◽  
pp. 166-177
Author(s):  
Соколовский ◽  
Yaroslav Sokolovskiy ◽  
Крошный ◽  
Igor Kroshnyy ◽  
Прусак ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mass Transfer ◽  
Plastic Deformation ◽  
Porous Materials ◽  
Heat Mass Transfer ◽  
Drying Process ◽  
Transfer Processes ◽  
Mass Transfer Processes ◽  
Mechanics Characteristics ◽  
A Current

In the paper there is described solving a current scientific problem of mathematical modeling of heat-mass transfer processes and elastic-viscous-plastic deformation taking into account the mechanics and sorption creep in hygroscopic capillary-porous materials with variable anisotropic heat and mechanics characteristics what is of importance for the rational choice and substantiation of energy conservative technologies of timber drying under the conditions of necessary qualitative production providing.

scholarly journals Modeling of kinetics of drying process of polycaproamide granules considering its sorption properties

2018 ◽  
Author(s):  
Marina Sergeevna Maklusova ◽  
Maria Konstantinovna Kosheleva ◽  
Olga Roaldovna Dornyak
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Mass Transfer ◽  
Moisture Content ◽  
Gas Phase ◽  
Heat And Mass Transfer ◽  
Sorption Properties ◽  
Convective Drying ◽  
Drying Process ◽  
Kinetics Of

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.

scholarly journals Modeling and simulation of heat and mass transfer in an Ethiopian fresh injera drying process

Heliyon ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. e06201
Author(s):  
Alamrew B. Solomon ◽  
Solomon W. Fanta ◽  
Mulugeta A. Delele ◽  
Maarten Vanierschot
Keyword(s):  
Mass Transfer ◽  
Modeling And Simulation ◽  
Heat And Mass Transfer ◽  
Drying Process

Method of Ginkgo biloba Drying and Drying Machine Design

2014 ◽  
Vol 541-542 ◽  
pp. 722-726
Author(s):  
Jun Ming Hou ◽  
De Xu Yang ◽  
Ke Jia Wu
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Convective Heat ◽  
Ginkgo Biloba ◽  
Medical Industry ◽  
Combined Effect ◽  
Machine Design ◽  
Drying Process ◽  
Heat Transmission ◽  
Electrically Conducting

In this paper the drying process of ginkgo biloba is discussed. The process combined effect of convective Heat and mass transfer on hydromagnetic electrically conducting viscous, how to improve the ability of drying is an important problem. The heat transmission for drying process is discussed. The parameter of drying process is determined. The ginkgo biloba drying machine is developed and the key part of drying machine is designed. The whole drying machine is developed, which can enhance the ability of medical industry. The study can help the Optimization of drying process and the level of the ginkgo biloba drying.

A mathematical model of turbulent heat and mass transfer in stably stratified shear flow

1993 ◽  
Vol 253 (-1) ◽  
pp. 341 ◽  
Author(s):  
G. I. Barenblatt ◽  
M. Bertsch ◽  
R. Dal Passo ◽  
V. M. Prostokishin ◽  
M. Ughi
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Shear Flow ◽  
Heat And Mass Transfer ◽  
Turbulent Heat ◽  
Stratified Shear Flow ◽  
Stably Stratified Shear Flow
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