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.

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 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

scholarly journals Processes of heat and mass transfer during drying of red beetroot

2020 ◽  
Vol 6 (2) ◽  
pp. 81-87
Author(s):  
Zhanna Petrova ◽  
◽  
Kateryna Samoilenko ◽  
Vitaly Vishnevsky
Keyword(s):  
Mass Transfer ◽  
Energy Consumption ◽  
Heat And Mass Transfer ◽  
Raw Materials ◽  
Antioxidant Properties ◽  
Calculation Model ◽  
Experimental Results ◽  
Biologically Active ◽  
Raw Material ◽  
Drying Process

Red beetroot is the main raw material which has a high content of betanine with antioxidant properties. An important emphasis in the processing of antioxidant raw materials by drying is to reduce energy consumption for the dehydration process, the maximum preservation of biologically active substances, and to reduce the cost of the final product. Drying is a complex and energy-intensive process. Therefore, to optimize energy consumption during drying and selection of rational modes of dehydration, it is necessary to apply the calculated analysis of heat and mass transfer on the basis of adequate mathematical models. Calculated and experimental results are compared. In general, the comparison of the results of numerical modeling of convection drying processes of the red beetroot sample with the experimental results showed their rather satisfactory qualitative agreement. The calculation model can be used to approximate the characteristics of the drying process of red beetroot, in particular the time required for drying. The obtained results of calorimetric studies allow stating that with correctly selected compositions, not only the components of native raw materials are stabilized, but also the drying process is intensified with the reduction of energy consumption to process.

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