Experimental Studies on Suspension of Solid Particles in a Low-Shear Stirred Vessel

2011 ◽  
Vol 34 (9) ◽  
pp. 1581-1586 ◽  
Author(s):  
X. Li ◽  
C. Yang ◽  
G. Zhang ◽  
Z.-S. Mao ◽  
H. Zhou
Keyword(s):  
Experimental Studies ◽  
Solid Particles ◽  
Stirred Vessel ◽  
Low Shear

scholarly journals Liquidation of solid particles of polydispersed grained material

2020 ◽  
Vol 3 (10) ◽  
pp. 319-321
Author(s):  
Bakhronov Koshim Shayimovich ◽  
Khudoiberdieva Nazora Sharofovna ◽  
Yunusova Sitora Tolib qizi
Keyword(s):  
Granular Materials ◽  
Fluidized Bed ◽  
Experimental Studies ◽  
Solid Particles ◽  
General Picture

The results of experimental studies on the study of the expansion of the fluidized bed are presented. It is noted that the general picture of the expansion of the fluidized bed of polydisperse granular materials differs from monodisperse systems, and at the same time the porosity value of the pseudo-fluidized bed corresponds to the results of calculations according to the equations available in the literature.

Turbulence Characteristics in a Rushton Stirring Vessel Measured via Time Resolved DPIV

2006 ◽  
Author(s):  
Michael R. Brady ◽  
Demetri P. Telionis ◽  
Pavlos P. Vlachos
Keyword(s):  
Experimental Studies ◽  
Turbulent Energy ◽  
Industrial Applications ◽  
Solid Particles ◽  
Analytical Models ◽  
Frequency Resolution ◽  
Time Resolved ◽  
Turbulence Characteristics ◽  
Stirred Vessels ◽  
Rushton Impeller

Stirred vessels are devices that find extensive industrial applications particularly in mineral and chemical industries. Interactions of solid particles and/or bubbles and particles depend on the characteristics of turbulent flow. In many analytical models, the rate of collision is a function of turbulence dissipation. It has been known that dissipation levels are much higher in the neighborhood of the agitating mechanism, in our case the Rushton impeller. In this paper we use time-resolved DPIV to measure the velocity field with a spatial resolution down to 100 μm, and a frequency resolution of 500 Hz. The range of Reynolds numbers investigated varied from 20,000 to 50,000, with the smallest Kolmogorov length scale of about 15 μm. The flow in the impeller stream of a Rushton impeller can be best summarized as a radial jet with a pair of convecting tip vortices. The turbulence quantities were found by removing the periodic component from the blade passing, which is the dominant part of the measured velocities. Dissipation was calculated from the velocity gradients, and assuming isotropy. We provide further evidence that larger dissipation values in the vicinity of the impeller are consistent with the dynamic motion generated by the blade passage. This is somewhat anti-intuitive, because energy is dissipated at the smallest eddy scales, and the immediate vicinity of the impeller contains large vortical structures and provides little space or time for such structures to break down. The maximum and mean normalized dissipation in the impeller stream showed decreasing trends with the Reynolds number. Other normalized turbulence quantities, namely Vrms and in plane vorticity are presented. Our experiments agree very well with other experimental studies. Estimates of turbulence characteristics and in particular distributions of turbulent energy dissipation determined in this study will be used in estimating rates of collisions of bubbles and particles in stirred vessels.

The effect of soil strength on germination and emergence of wheat (Triticum aestivum L.). I. Low shear strength conditions

Soil Research ◽  
1985 ◽  
Vol 23 (4) ◽  
pp. 577 ◽  
Author(s):  
N Collis-George ◽  
P Yoganathan
Keyword(s):  
Triticum Aestivum ◽  
Shear Strength ◽  
Root Elongation ◽  
Experimental Studies ◽  
Fine Sand ◽  
Triticum Aestivum L ◽  
Initial Soil ◽  
Soil Shear Strength ◽  
Coleoptile Elongation ◽  
Low Shear

Experimental studies of the germination and emergence of wheat as affected by soil shear strength are reported. A fine sand under saturated conditions was used as the seed bed and the shear strength of the seed bed was increased to 10 kPa (0.1 bar) by externally applied loads. From the results it is concluded that the initial soil shear strength in this range has little effect on germination. However, coleoptile growth and root elongation are markedly reduced in the range 0-2.2 kPa such that total emergence is reduced to 7% at 9.3 kPa in this fine sand. The results clearly show that coleoptile elongation is more affected than root elongation by the same mechanical stress. Roots are found to be thicker and coleoptile thinner under increasing soil shear strength conditions.

scholarly journals Loss coefficients of ice slurry in sudden pipe contractions

2010 ◽  
Vol 31 (3) ◽  
pp. 73-86
Author(s):  
Łukasz Mika
Keyword(s):  
Mass Fraction ◽  
Flow Resistance ◽  
Volume Fraction ◽  
Experimental Studies ◽  
Solid Particles ◽  
Minimal Flow ◽  
Ice Slurry ◽  
Slurry Flow ◽  
Flow Through ◽  
Loss Coefficients

Loss coefficients of ice slurry in sudden pipe contractionsIn this paper, flow systems which are commonly used in fittings elements such as contractions in ice slurry pipelines, are experimentally investigated. In the study reported in this paper, the consideration was given to the specific features of the ice slurry flow in which the flow behaviour depends mainly on the volume fraction of solid particles. The results of the experimental studies on the flow resistance, presented herein, enabled to determine the loss coefficient during the ice slurry flow through the sudden pipe contraction. The mass fraction of solid particles in the slurry ranged from 5 to 30%. The experimental studies were conducted on a few variants of the most common contractions of copper pipes: 28/22 mm, 28/18 mm, 28/15 mm, 22/18 mm, 22/15 mm and 18/15 mm. The recommended (with respect to minimal flow resistance) range of the Reynolds number (Re about 3000-4000) for the ice slurry flow through sudden contractions was presented in this paper.

scholarly journals Dielectric Properties and Substantiation of Electromagnetic Technologies for Oil Sludge Processing

2020 ◽  
Author(s):  
Eldar Rinatovich Abdeev ◽  
Minikhan Abuzarovich Fatykhov ◽  
Rail Idiatovich Saitov ◽  
Rinat Gazizyanovich Abdeev ◽  
Lenart Minnehanovich Fatykhov
Keyword(s):  
Electromagnetic Field ◽  
Dielectric Properties ◽  
Atmospheric Oxygen ◽  
Experimental Studies ◽  
Solid Particles ◽  
Oil Sludge ◽  
Water Contact ◽  
Long Term Storage ◽  
Oil Storage ◽  
Oil Water

In the process of reception, storage and preparation of oil for processing, significant volumes of oil-containing sludge are formed, which are not only a source of pollution, but also a valuable hydrocarbon feedstock. Long-term storage of oil with water, contact with atmospheric oxygen, and the presence of solid particles hydrophobized with asphalt-resinous and paraffinous substances contribute to the formation of “intermediate layers” in these sludges, which are ultra-stable oil-water emulsions. It is proposed to use the energy of the electromagnetic field of the high and microwave ranges when developing a technology for the destruction of oil-water emulsions. After analyzing the composition of the oil sludge, experimental studies were conducted of the dielectric loss tangenttgδδ of oil with the addition of sand and paraffin, depending on the frequency of electromagnetic oscillations in the range of 30 - 160 MHz and temperature in the range of 25 - 80 ∘ С using the cumeter method. Studies have shown that two technologies for the disposal of oil sludge are possible: HF and UHF methods. To assess the effectiveness of their application, it is necessary to conduct experimental studies of the dielectric properties of oil sludge. Keywords: oil sludge, oil sludge disposal,oil storage, oil-water emulsions, electromagnetic field

scholarly journals Transport of Solid Particles with Fluid Flow in Rotating Pipes

2019 ◽  
Vol 9 (2) ◽  
pp. 201-206
Author(s):  
F.Sh. Zabirov ◽  
B.M. Latypov ◽  
R.G. Sharafiev ◽  
R.A. Gilmanshin
Keyword(s):  
Fluid Flow ◽  
Experimental Studies ◽  
Equation System ◽  
Solid Particles ◽  
Sand Transport ◽  
Operating Life ◽  
Surface Type ◽  
Horizontal Pipe ◽  
Study Results ◽  
Carry Over

Abstract The article addresses the recent problem of borehole lifting of oil containing sand solids. The presence of sand in oil produced results in a reduced operating life of downhole equipment. The problem of preventing sanding up and sand formation in pumping equipment may be solved and stable sand production may be ensured by producing oil using borehole screw pumps with a surface-type drive, in which the screw is rotated by rotating hollow rods. Rotating hollow rods improve carry-over of sand particles to the surface with rotational oil flow by imparting additional momentum to these particles. Rotational variables of the pipe (cylinder) that enables transport of solids are set only for the air flow moving in a horizontal pipe (cylinder). The purpose of the study is to establish pipe rotational variables in directional wells that enable stable sand transport with fluid flow. Work results have been obtained from numerical studies using the differential equation system and rules of theoretical solid movement, computer simulation and experimental results processing at a laboratory facility. Theoretical study results have been acknowledged by experimental studies. The work establishes the criteria that allow defining the speed range of directional hollow rods that enables carry-over of solids to the surface with fluid flow. Study results may be used to produce oil with submersible screw pumps with a surface-type drive that use hollow sucker rods for pump down.

Influence of suspended solid particles on gas-liquid mass transfer coefficient in a system stirred by double impellers

2009 ◽  
Vol 63 (2) ◽  
Author(s):  
Anna Kiełbus-Rąpała ◽  
Joanna Karcz
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
High Speed ◽  
Gas Flow ◽  
Research Work ◽  
Experimental Studies ◽  
Solid Particles ◽  
Solid Concentration ◽  
Volumetric Mass Transfer Coefficient

AbstractThe aim of the research work was to investigate the effect of the presence and concentration of solid particles on the gas-liquid volumetric mass transfer coefficient in a mechanically stirred gas-solid-liquid system. Experimental studies were conducted in a tall vessel of the diameter of 0.288 m, equipped with two designs of double stirrers. Three high-speed stirrers were used: A 315, Smith turbine, and Rushton turbine. The following operating parameters were changed: gas flow rate, stirrer speed, and solid concentration. The volumetric mass transfer coefficient was determined using the dynamic gassing-out method. In the range of the measurements conducted, this coefficient was strongly affected by both the presence and the concentration of particles in the system. Generally, a low concentration of particles in the system, equal to 0.5 mass %, caused an increase of the volumetric mass transfer coefficient values for both stirrer configurations compared to a system without solids whilst more particles (2.5 mass %) caused a decrease of this coefficient. It could be supposed that an increase of slurry viscosity affected the decrease of the volumetric mass transfer coefficient at higher solid concentration. An empirical correlation was proposed for volumetric mass transfer coefficient prediction. Its parameters were fitted using experimental data.

scholarly journals CLARIFICATION OF AQUEOUS SUSPENSIONS WITH A HIGH CONTENT OF SUSPENDED SOLIDS IN RAPID SAND FILTERS

2019 ◽  
Vol 1 ◽  
pp. 28-45 ◽  
Author(s):  
Vadym Polyakov ◽  
Andriy Kravchuk ◽  
Gennadii Kochetov ◽  
Oleksandr Kravchuk
Keyword(s):  
Filtration Rate ◽  
Volume Concentration ◽  
Experimental Studies ◽  
Solid Particles ◽  
High Concentration ◽  
Sand Filters ◽  
Measured Variable ◽  
Actual Problem ◽  
Pressure Losses ◽  
Filter Loading

The presented work is devoted to solving the actual problem of increasing the efficiency of rapid sand filters with granular filling, which operate at a constant filtration rate when cleaning suspensions with a relatively high concentration of contaminants. The proposed mathematical model for clarifying the suspension by filtration consists of three interconnected blocks: clarified, filtration, and hydraulic. Convenient dimensionless mathematical dependencies are obtained for calculating the concentrations of contaminants and sediment from the height of the filter and suspension in the filtrate; head loss in the filter loading; the effective time of the filter (the duration of the filter cycle). The design of the experimental setup and the methodology for conducting experimental studies and mathematical processing of the results are valid. The results of experimental studies of the suspension filtering process through the granular loading are presented, and the obtained data is analyzed. Measurement of pressure losses in the filter loading is performed when a suspension is passed with a relatively high concentration of contaminants at various filtration rates. The nature of the change in the filtration rate with time and height (length) loading at various filtration rates and initial contamination concentrations is determined. Measured variable concentration of suspended matter in filtered water and retained contamination over time. As a result of the experiments, it is confirmed that an increase in the concentration of retained contaminants S leads to an increase in the parameter Δn/n. Upon reaching a certain value of the concentration of the retained sediment S (in our case S=30 g/dm3), an increase in the relative specific volume of the sediment greater than Δn/n0=0.65 is not observed. It is established that an important characteristic of the retained sediment is the ratio of the volume concentration of the sediment to the volume concentration of solid particles in this sediment γ=Csd/Сs. The values of the adhesion and detachment of particles of contaminant in the particles of the material loading =4,9; =0,009. The results of experimental studies in general confirm the correctness and reliability of the obtained analytical dependencies.

INFLUENCE OF BRAKE RECOVERY ON EMISSIONS OF SOLID PARTICLES FROM CARS

2020 ◽  
Vol 71 (4) ◽  
pp. 61-68
Author(s):  
V.A. RAKOV ◽  
Keyword(s):  
Fine Particles ◽  
Experimental Studies ◽  
Solid Particles ◽  
Regenerative Braking

The main objectives of the study are to establish the effect of regenerative braking on emis-sions of fine particles from the wear of brake mechanisms. The main objective is to develop assess-ment methods. In the experimental studies involved vehicles with a hybrid engine, which performed a series of acceleration and braking cycles with recovery, and then only mechanical braking. The presented results allow us to draw conclusions about the effect of regenerative braking on emis-sions from wear on brake linings.

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