Filter Characteristics of Porous Wire Gauze Partitions

2019 ◽  
Vol 7 (4) ◽  
pp. 43-48
Author(s):  
В. Спиридонов ◽  
V. Spiridonov ◽  
О. Кирикова ◽  
O. Kirikova ◽  
А. Ельчанинов ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Experimental Studies ◽  
Particle Diameter ◽  
Calculated Data ◽  
Spherical Particles ◽  
Hydrodynamic Mode ◽  
Wire Gauze ◽  
Leakage Coefficient ◽  
Square Cells ◽  
Wire Meshes

The article presents the results of experimental studies of the uneven distribution of the distances between the wires of the warp and weft in woven wire meshes with square cells used to clean gases and liquids from mechanical impurities in various branches of technology. On the basis of experimental data using the methods of probability theory, the regularity of the size distribution of the cells of these grids is determined. The length of its minimum side is chosen as the determining size of a square cell. The results of the conducted studies were used to estimate the fractional coefficient of the leakage of spherical particles through the mesh in the sieve mechanism of separation of these particles from the fluid flow. The probability of particle breakthrough through the grid is assumed to be equal to the fraction of the fluid flow passing through the cells, which determines the size of which is larger than the particle diameter. For experimental verification of the calculated values of the leakage coefficient for the sieve filtering mechanism, a preliminary analysis of the influence of the parameters of the hydrodynamic mode of fluid flow through the grid and the level of fluid contamination on the filtering mechanism was carried out. The results of experimental studies of the fractional leakage coefficient values obtained by the sieve filtering mechanism are compared with the calculated data.

Adsorption of safranine T from aqueous medium by nano mesoporous MCM-41: adsorption equilibrium, kinetics, and thermodynamics

2020 ◽  
Vol 10 ◽  
Author(s):  
Xiao-Dong Li ◽  
Qing-Zhou Zhai
Keyword(s):  
Electron Microscopy ◽  
Ph Value ◽  
Particle Diameter ◽  
Spherical Particles ◽  
Practical Significance ◽  
Average Particle ◽  
Average Pore ◽  
Kinetics And Thermodynamics ◽  
Safranine T ◽  
Mcm 41

Introduction: In industrial production, a small amount of saffron T emissions will cause increase of water color and increase of chemical oxygen consumption, so study of the decolorization of saffron T wastewater has an important practical significance. Methods: MCM (Mobil Composition of Matter)-41 molecular sieve was synthesized by hydrothermal method. Power Xray diffraction and scanning electron microscopy were used to characterize the sample. Safranine T dye was adsorbed from water by the MCM-41 prepared. Kinetics and thermodynamics of the adsorption were studied. Results: The MCM-41 sample presented spherical particles and regular. The BET (Brunner-Emmett-Teller) specific surface area of the sample determined by 77 K low temperature nitrogen adsorption-desorption isotherm was 932 m2 /g. Its average particle diameter was 110 nm. TEM (transmission electron microscopy) results showed that the sample structure presented a honeycomb pore structure and the average pore diameter was 3.0 nm. The results showed that when room temperature was 20 ± 1 ℃, adsorbate safranine T: adsorbent MCM-41 = 20 : 1，the optimum pH value of adsorption was 4.0 and contact time was 20 min, the adsorption rate reached 98.29% and the adsorption capacity was 19.66 mg/g. The entropy change and enthalpy change of the adsorption system are respectively ΔS0 = 157.5 J/(mol·K); ΔH0 = 21.544 kJ/mol. When temperature was 277.15, 293.15, 303.15 K，the free energy change was respectively △G1 0 = -22.107 kJ/mol, △G2 0 = -24.627 kJ/mol, △G3 0 = -26.202 kJ/mol. Conclusion: The adsorption of safranine T by MCM-41 belongs to a pseudo-second-order adsorption. This adsorption accords with the Freundlich equation and belongs to a heterogeneous adsorption. The adsorption is an endothermic reaction of entropy increase, being spontaneous.

scholarly journals Influence of Macroscopic Wall Structures on the Fluid Flow and Heat Transfer in Fixed Bed Reactors with Small Tube to Particle Diameter Ratio

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 689
Author(s):  
Thomas Eppinger ◽  
Nico Jurtz ◽  
Matthias Kraume
Keyword(s):  
Heat Transfer ◽  
Fixed Bed ◽  
Particle Diameter ◽  
Diameter Ratio ◽  
Spherical Particles ◽  
Reactor Wall ◽  
Entry Length ◽  
Fixed Bed Reactors ◽  
Wall Structures ◽  
Small Tube

Fixed bed reactors are widely used in the chemical, nuclear and process industry. Due to the solid particle arrangement and its resulting non-homogeneous radial void fraction distribution, the heat transfer of this reactor type is inhibited, especially for fixed bed reactors with a small tube to particle diameter ratio. This work shows that, based on three-dimensional particle-resolved discrete element method (DEM) computational fluid dynamics (CFD) simulations, it is possible to reduce the maldistribution of mono-dispersed spherical particles near the reactor wall by the use of macroscopic wall structures. As a result, the lateral convection is significantly increased leading to a better radial heat transfer. This is investigated for different macroscopic wall structures, different air flow rates (Reynolds number Re = 16 ...16,000) and a variation of tube to particle diameter ratios (2.8, 4.8, 6.8, 8.8). An increase of the radial velocity of up to 40%, a reduction of the thermal entry length of 66% and an overall heat transfer increase of up to 120% are found.

Experimental and Analytical Assessment of the Power Parameters of the Combined Rolling-Extruding Process Using a Round Billet from Alloy 01417 Obtained Using an Electromagnetic Mold

2021 ◽  
Vol 887 ◽  
pp. 300-305
Author(s):  
S. Sidelnikov ◽  
D. Voroshilov ◽  
M. Motkov ◽  
V. Bespalov ◽  
M. Voroshilova
Keyword(s):  
Experimental Studies ◽  
Calculated Data ◽  
Laboratory Unit ◽  
Round Billet ◽  
Power Load ◽  
Industrial Unit ◽  
Analytical Assessment

Analytical and experimental studies have been carried out, which made it possible to propose new technological modes of combined rolling-extruding for the production of rods from alloy 01417 for the further drawing of wire for electrical purposes. The force parameters on the rolls and the die are calculated when extruding a rod with a diameter of 5 mm on the laboratory unit CRE-200 and the industrial unit CRE-400. The obtained values of the forces on the rolls and the die do not exceed the permissible values of the power load of the units. Therefore the selected parameters are suitable for conducting experiments on the manufacture of prototypes of rods. To verify the conclusions made, experimental studies were carried out on the CRE-200 unit at a temperature of 320 oC and a drawing coefficient μ = 12.1. The results of experimental studies in comparison with the calculated data showed that the deviation of the calculated data does not exceed 15%.

Settling Behavior of Particles in Bubble Containing Newtonian Fluids: Experimental Study and Model Development

2021 ◽  
Author(s):  
Silin Jing ◽  
Xianzhi Song ◽  
Zhaopeng Zhu ◽  
Buwen Yu ◽  
Shiming Duan
Keyword(s):  
Reynolds Number ◽  
Drag Coefficient ◽  
Volume Concentration ◽  
Settling Velocity ◽  
Particle Density ◽  
Particle Diameter ◽  
Newtonian Fluids ◽  
Spherical Particles ◽  
Bubble Volume ◽  
Particle Reynolds Number

Abstract Accurate description of cuttings slippage in the gas-liquid phase is of great significance for wellbore cleaning and the control accuracy of bottom hole pressure during MPD. In this study, the wellbore bubble flow environment was simulated by a constant pressure air pump and the transparent wellbore, and the settling characteristics of spherical particles under different gas volume concentrations were recorded and analyzed by highspeed photography. A total of 225 tests were conducted to analyze the influence of particle diameter (1–12mm), particle density (2700–7860kg/m^3), liquid viscosity and bubble volume concentration on particle settling velocity. Gas drag force is defined to quantitatively evaluate the bubble’s resistance to particle slippage. The relationship between bubble drag coefficient and particle Reynolds number is obtained by fitting the experimental results. An explicit settling velocity equation is established by introducing Archimedes number. This explicit equation with an average relative error of only 8.09% can directly predict the terminal settling velocity of the sphere in bubble containing Newtonian fluids. The models for predicting bubble drag coefficient and the terminal settling velocity are valid with particle Reynolds number ranging from 0.05 to 167 and bubble volume concentration ranging from 3.0% to 20.0%. Besides, a trial-and-error procedure and an illustrative example are presented to show how to calculate bubble drag coefficient and settling velocity in bubble containing fluids. The results of this study will provide the theoretical basis for wellbore cleaning and accurate downhole pressure to further improve the performance of MPD in treating gas influx.

scholarly journals Experimental and Theoretical Study of the Axial Distribution of Solid Phase Particles in a Fluidized Bed

2021 ◽  
Vol 64 (4) ◽  
pp. 349-362
Author(s):  
A. V. Mitrofanov ◽  
V. E. Mizonov ◽  
N. S. Shpeynova ◽  
S. V. Vasilevich ◽  
N. K. Kasatkina
Keyword(s):  
Fluidized Bed ◽  
Field Experiments ◽  
Solid Phase ◽  
Cell Model ◽  
Experimental Studies ◽  
Parametric Identification ◽  
Resistance Coefficient ◽  
Model Material ◽  
Spherical Particles ◽  
Axial Distribution

The article presents the results of computational and experimental studies of the distribution of a model material (plastic spherical particles with a size of 6 mm) along the height of a laboratory two-dimensional apparatus of the fluidized bed of the periodic principle of action. To experimentally determine the distribution of the solid phase over the height of the apparatus, digital photographs of the fluidized bed were taken, which were then analyzed using an algorithm that had been specially developed for this purpose. The algorithm involved splitting the image by height into separate rectangular areas, identifying the particles and counting their number in each of these areas. Numerical experiments were performed using the previously proposed one-dimensional cell model of the fluidization process, constructed on the basis of the mathematical apparatus of the theory of Markov chains with discrete space and time. The design scheme of the model assumes the spatial decomposition of the layer in height into individual elements of small finite sizes. Thus, the numerically obtained results qualitatively corresponded to the full-scale field experiment that had been set up. To ensure the quantitative reliability of the calculated forecasts, a parametric identification of the model was performed using known empirical dependencies to calculate the particle resistance coefficient and estimate the coefficient of their macrodiffusion. A comparison of the results of numerical and field experiments made us possible to identify the most productive empirical dependencies that correspond to the cellular scheme of modeling the process. The resulting physical and mathematical model has a high predictive efficiency and can be used for engineering calculations of devices with a fluidized bed, as well as for setting and solving problems of optimal control of technological processes in these devices for various target functions.

Micromechanical Analysis of Nonlinear Response of Unidirectional Composites: A Fundamental Approach

2001 ◽  
Author(s):  
Virendra R. Jadhav ◽  
Srinivasan Sridharan
Keyword(s):  
Mechanical Model ◽  
Nonlinear Response ◽  
Experimental Studies ◽  
Matrix Cracking ◽  
Type Model ◽  
Unidirectional Composites ◽  
The Matrix ◽  
Experimental Response ◽  
Square Cells ◽  
Experimental Comparisons

Abstract Micromechanical models with different representative volume elements have been developed to study their ability to predict nonlinear response of unidirectional composites. A simple, square cells type micro-mechanical model similar to those widely used by other researchers is compared with a more advanced 3-phase finite element based micro-mechanical model. The models utilize the “bulk” properties of the matrix without attempting to “tune” the model to fit with experimental response of laminae. This is a more fundamental approach and constitutes a departure from current practice. The models account for shear softening, matrix cracking and the presence of residual stresses. A smeared cracking approach was used to characterize the micro-cracking in matrix. Experimental studies were performed on laminae, laminates and cylinders made from carbon epoxy composites. Experimental comparisons show that the more accurate micro-mechanical model with proper partial cracking options provides good bounds on experimental response with consistent accuracy. A square cells type model however is not consistent in its predictions, thus raising questions about its applicability in any general micro-mechanics based analysis.

An Experimental Study of Fluid Flow in Disk Cavities

1992 ◽  
Vol 114 (2) ◽  
pp. 454-461 ◽  
Author(s):  
S. H. Bhavnani ◽  
J. M. Khodadadi ◽  
J. S. Goodling ◽  
J. Waggott
Keyword(s):  
Experimental Study ◽  
Fluid Flow ◽  
Gas Turbine ◽  
Experimental Studies ◽  
Reynolds Numbers ◽  
Turbine Disk ◽  
Published Data ◽  
Disk System ◽  
Flow Rates ◽  
Pressure Distributions

Results are presented for an experimental study of fluid flow in models of gas turbine disk cavities. Experiments were performed on 70-cm-dia disks for rotational Reynolds numbers up to 2.29 × 106. Velocity and pressure distributions are presented and compared to previous theoretical and experimental studies for a free disk, and an unshrouded plane Rotor–Stator disk system. Minimum coolant flow rates for the prevention of ingress, determined for the case of a simple axial rim seal, compare well with previously published data.

Strength and Deformation of Combined Beams with Side Reinforced Plates

2019 ◽  
Vol 968 ◽  
pp. 234-239
Author(s):  
Talyat Azizov ◽  
Oleksii Melnik ◽  
Oleksandr Myza
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Experimental Studies ◽  
Calculated Data ◽  
Concrete Plate ◽  
Combined Action ◽  
Strength And Deformation ◽  
Concrete Plates ◽  
Good Agreement

The results of experimental studies of combined beams consisting of a stone part, reinforced with side reinforced concrete plates are given. Experimentally shown the viability of the proposed structures. The conditions for ensuring the combined action of a stone beam and a reinforced concrete plate are given. Cases are shown when one-sided plates can be used and when double-sided reinforced concrete plates can be used. A comparison of experimental data with the data calculated by the authors developed methods is given. A good agreement between theoretical and calculated data is shown.

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