scholarly journals Mathematical processing of results experimental studies of low-temperature modes of drying of capillary-porous materials of spherical shape

2019 ◽  
pp. 20-25
Author(s):  
Yu.F. Snezhkin ◽  
V.М. Paziuk ◽  
Zh.O. Petrova
Keyword(s):  
Mathematical Model ◽  
Low Temperature ◽  
Porous Materials ◽  
Experimental Studies ◽  
Spherical Shape ◽  
Response Surfaces ◽  
Convective Drying ◽  
Regression Equations ◽  
Drying Time ◽  
Mathematical Processing

The mathematical processing of experimental data obtained during the drying of spherical form of capillary-porous materials on a convective drying bench allows us to determine the influence of various factors on the process. The main factors influencing the kinetics of drying of capillary-porous materials of spherical shape are the temperature and velocity of the heat carrier, as well as the initial moisture content of the material. For each factor, the variation levels corresponding to the optimal conditions for conducting experimental studies with low-temperature drying conditions are recommended. For a mathematical description of the duration of drying of capillary-porous materials, we use an orthogonal composite plan of the second order. As a result, the proposed mathematical model of the process obtained regression equations and the response surface of the duration of drying of capillary-porous materials of spherical shape. The obtained regression equations of the drying time give a detailed description of the influence of both individual and joint actions of factors, the significance of these parameters is determined by the corresponding coefficients according to Student's criterion. Also, the adequacy of the mathematical model according to Fisher's criterion, which corresponds to the real object, is checked. The construction of the response surfaces of the drying time of capillary-porous materials indicates the nature of the effect of these factors in the given range of variation.

scholarly journals Heat pump technologies of low temperature drying of capillary-porous materials spherical shape

2020 ◽  
pp. 7-12
Author(s):  
Yu.F. Snezhkin ◽  
V.М. Paziuk ◽  
Zh.O. Petrova
Keyword(s):  
Low Temperature ◽  
Porous Materials ◽  
Heat Pump ◽  
Experimental Studies ◽  
Average Energy ◽  
Spherical Shape ◽  
High Energy ◽  
Heat Pumps ◽  
Heat Pump Drying ◽  
Low Temperature Drying

Heat pump technologies have become widely used in space heating and air conditioning systems, and the heat pump can be used for low-temperature drying of capillary-porous materials. Recuperative and condensing heat pumps, which allow both drying and cooling of the material, have become the most widespread. The developed condensing heat pump drying unit with a mine chamber implements a low-temperature drying process of spherical capillary-porous materials at a drying agent temperature of 40-50°C with a decrease in material humidity by 11% to a final humidity of 8%. Experimental studies on a heat pump drying unit for drying capillary-porous materials of spherical shape indicated a significant reduction in average energy costs per process up to 3700 - 4100 kJ/kg of evaporated moisture. The increase in energy consumption increases significantly in the second part of the second period, where heat consumption can reach 5000 - 5350 kJ/kg of evaporated moisture. The use of condensing heat pumps for low-temperature drying of capillary-porous materials has shown high energy efficiency compared to existing drying technologies.

scholarly journals Investigation of low-temperature drying modes plant capillary-porous materials spherical shape

2018 ◽  
pp. 7-14
Author(s):  
V.М. Pazyuk
Keyword(s):  
Porous Materials ◽  
Heat Carrier ◽  
Experimental Studies ◽  
Spherical Shape ◽  
Convective Drying ◽  
Drying Rate ◽  
Drying Process ◽  
Exchange Processes ◽  
Low Temperature Drying ◽  
Kinetics Of

The results of experimental studies of the drying of capillary-porous materials of spherical shape from the influence of the temperature of the heat carrier are given.Spherical granules with a diameter of 2,2 mm were taken to determine the rational modes of drying of capillary-porous materials. For a better evaluation of the nature of the drying process, experimental design studies were carried out on a convective drying stand in an elementary layer.The program of automatic collection and processing of information allows obtaining data on changes in the mass and temperature of the sample during the removal of moisture, and also performs calculations of kinetics of drying in absolute and relative coordinates. This makes it possible to obtain and compare the kinetic and velocity characteristics of colloid capillary-porous materials drying faster, more accurately and reliably.By the method of Krasnikov V.V. the kinetics of drying of capillary-porous materials of spherical shape with a diameter of 2,2 mm with construction of a generalized drying curve with determination and calculation of drying coefficients is considered.The generalized curve of drying rate is constructed and obtained, which allows us to generalize the process of drying of a capillary-porous spherical material. Also, get the formula and determine the overall length of the drying process through the drying rate for each heat treatment.When comparing the values of the process length obtained by experimental studies and determined by the calculations, the experimental error from the calculation does not exceed 3%.The analysis of heat-mass-exchange processes of drying by means of calculations of temperature coefficient b, Rebinder Rb criterion, heat flow q and coefficient of heat transfer α from the influence of heat carrier temperature has been carried out.

scholarly journals DRYING WHITE CABBAGE ON A CONVECTIVE DRYING BENCH

2021 ◽  
Vol 43 (3) ◽  
pp. 24-29
Author(s):  
Zh. Petrova ◽  
V. Paziuk ◽  
P. Vishnevsky ◽  
D. Grakov ◽  
О. Grakov
Keyword(s):  
Raw Materials ◽  
Rapid Heating ◽  
Experimental Studies ◽  
Visual Assessment ◽  
Convective Drying ◽  
Drying Methods ◽  
Drying Time ◽  
White Cabbage ◽  
Infrared Method

Known methods of production of dried cabbage are long-term production processes that take place within 12… 24 hours. Therefore, it is necessary to develop new methods of drying and intensification of this process. The article presents experimental studies of the kinetics of the drying process of white cabbage with different energy supply and their combinations, such as convective, infrared and convective-infrared drying methods. The main criterion for choosing a rational mode of drying is the quality of raw materials after heat treatment, in particular the visual assessment of color by temperature. During convective drying, the analysis of temperature regimes for process intensity and quality of raw materials was performed. The drying mode of 60ºC which satisfies all requirements for quality of material was chosen. To speed up the process, it is proposed to reduce the drying time by introducing a step mode of 80 / 60ºC, which also reduces the energy component. Infrared radiation intensifies the process due to the rapid heating of the material, but in turn it burns. Therefore, a combined convective-infrared method is proposed in which the temperature in the product did not exceed 60 ° C. This method of drying showed good results with a shorter drying time.Infrared radiation intensifies the process due to the rapid heating of the material, but in turn it burns. Therefore, a combined convective-infrared method is proposed in which the temperature in the product did not exceed 60 ° C. This method of drying showed good results with a shorter drying time.

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 KINETICS OF THE PROCESS OF DRYING THE PASTE OF TITANIUM DIOXIDE IN AN ORIGINAL DRYING VORTEX APPARATUS AND OBTAINING A FINE POWDER TIO2

2018 ◽  
pp. 23-29
Author(s):  
V.M. Marchevskii ◽  
Ya.V. Grobovenko
Keyword(s):  
Mathematical Model ◽  
Titanium Dioxide ◽  
Experimental Studies ◽  
Fine Powder ◽  
State Standards ◽  
Drying Rate ◽  
Drying Process ◽  
Residual Moisture ◽  
Drying Time ◽  
Vortex Apparatus

The authors of the article justified the physical model of the drying process of titanium dioxide paste and the drying of TiO2 fine powder to a residual moisture content of 0.3%, on the basis of which a mathematical model of the drying process is developed. The result of solving the mathematical model is the kinetic parameters of the drying process, with the help of which the drying apparatus of the vortex type was designed, designed and manufactured. The results of the simulation were verified by experimental studies of the drying and drying of TiO2 paste, and experimental graphical dependences of the drying rate and product temperature on the drying time were obtained. The obtained dependences are analyzed and the necessary initial parameters of the coolant are established, which allow increasing the drying rate and reducing energy costs for the drying process. As a result of the experiments, the fine powder of titanium dioxide fits the requirements of state standards and possesses the necessary mechanical and consumer properties. Bibl. 10, Fig. 7.

scholarly journals Results of experiments to determine the traction resistance of a disk working body

2020 ◽  
Vol 222 ◽  
pp. 03006
Author(s):  
Rustem Sakhapov ◽  
Ramil Gainutdinov ◽  
Marat Mahmutov ◽  
Minsur Zemdikhanov
Keyword(s):  
Rotation Axis ◽  
Experimental Studies ◽  
Soil Surface ◽  
Response Surfaces ◽  
Regression Equations ◽  
Technical Requirements ◽  
Spatial Movement ◽  
Working Bodies ◽  
The Mathematical Model ◽  
Physical Quantities

Technical means used for soil surface treatment do not fully meet the technical requirements for high-quality soil treatment. In order to solve this problem more effectively, various rotary machines with working bodies that perform complex spatial movement are currently being developed. But, as practice has shown, that the work of these tools is unstable and that the cultivation of the soil is carried out unevenly. To eliminate these disadvantages, we developed a tillage tool with ellipsoid disk working bodies mounted on the shaft at a strictly defined angle [7, 13]. The analysis showed that to ensure the efficiency of work and reduce the traction resistance of tools for tillage, it is necessary that the angle of installation of the ellipsoid disk abount rotation axis is also optimal. Here are the results of experimental studies of the traction resistance of disks conducted in the conditions of a soil channel. The mathematical model of the technological process was obtained by processing experimental data in the computer program “Statistica” and presented in the form of multiple regression equations in encoded and real physical quantities. The response surfaces are constructed based on the obtained equations.

scholarly journals Drying of red beetroot after osmotic pretreatment: Kinetics and quality considerations

2015 ◽  
Vol 36 (3) ◽  
pp. 345-354 ◽  
Author(s):  
Stefan J. Kowalski ◽  
Joanna M. Łechtańska
Keyword(s):  
Water Activity ◽  
Osmotic Dehydration ◽  
Experimental Studies ◽  
Nutrient Content ◽  
Convective Drying ◽  
Drying Time ◽  
Solid Gain ◽  
Nacl Concentration ◽  
Osmotic Agent ◽  
Content Preservation

Abstract This article presents experimental studies on drying kinetics and quality effects of red beetroot (Beta vulgaris L.) after convective drying with a preliminary osmotic pretreatment. The effects of the osmotic agent (NaCl) concentration and the osmotic bath time on the product colour and nutrient content preservation, the water activity, and rehydration ability after drying were analysed. Osmotic dehydration curves and Solid Gain (SG), Water Loss (WL), Weight Reduction (WR) were determined. It was proved that drying of beetroot with osmotic pretreatment contributes to shorter drying time, smaller water activity, higher retention of betanin, better colour preservation, and a greater degree of water resorption.

scholarly journals Mathematical simulation of separating work tool technological process

2019 ◽  
Vol 132 ◽  
pp. 01025
Author(s):  
Sylwester Tabor ◽  
Aleksandr Lezhenkin ◽  
Serhii Halko ◽  
Aleksandr Miroshnyk ◽  
Stepan Kovalyshyn ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Mathematical Simulation ◽  
Technological Process ◽  
Response Function ◽  
Mathematical Analysis ◽  
Response Surfaces ◽  
Regression Equations

The article describes the technological process of separation of the heaped-off pile of wheat. A mathematical model in the form of regression equations was obtained based on a full-factor experiment. Using the methods of mathematical analysis, the regression equations were investigated for the highest and lowest values. The values of the factors were obtained, for which the response function has the highest values, then the response surfaces were constructed and analyzed.

scholarly journals Impoving the quality of products created by additive technologies on the basisi of tig welding

2021 ◽  
Vol 5 (1) ◽  
pp. 103-112
Author(s):  
Alexander Salenko ◽  
А. Kostenko ◽  
D. Tsurkan ◽  
Oleksii Samoilenko ◽  
Olga Chencheva ◽  
...  
Keyword(s):  
Dynamic Stability ◽  
Experimental Studies ◽  
Response Surfaces ◽  
Geometric Parameters ◽  
Tig Welding ◽  
Layer By Layer ◽  
Regression Equations ◽  
Proposed Model ◽  
Quality Of Products

The paper deals with the issues of obtaining the minimum waviness of surfaces formed by additive processes of TIG welding. It is known that the geometric parameters of the melt bead, which form a reproducible workpiece layer by layer, are determined by both the energy and kinematic characteristics of the process. In this case, the laying of the rollers occurs with optimal overlap, as a result of which it is possible to achieve the maximum density of the model, however, with the simultaneous appearance of a certain waviness due to thermodynamic phenomena in the melt bath. The proposed model of the formation of a bead of melt, the use of which made it possible to establish the rational conditions for laying out the layers. Experimental studies of the process of argon-arc surfacing of models of a given, regression equations for determining the controlled waviness parameter are obtained. It is shown that the waviness parameter is influenced by dynamic phenomena and wave processes that develop under the action of a system of forces during the formation of a melt bead. An improvement in the quality of products is seen in the optimization of the methods of forming the rollers, in ensuring the dynamic stability of the movement of the working head, ensuring the appropriate overlap of the trajectories of movement along the layers of the layout by an amount of 0.5e, establishing a rational arc length, and maintaining the dynamic stability of the arc burning. The response surfaces of the objective functions in the planes of the process parameters are constructed, which provide a clear illustration of the dependence of the controlled geometric parameters on the welding modes.

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