Liquid velocity interval for minimum liquid fluidization of binary solids mixtures

The study describes simulation of the motion of bubbles in gas, dispersed by a mechanical impeller in a turbulent low-viscosity liquid flow. The model employs the Monte Carlo method and it is based both on the knowledge of the mean velocity field of mixed liquid (mean motion) and of the spatial distribution of turbulence intensity ( fluctuating motion) in the investigated system - a cylindrical tank with radial baffles at the wall and with a standard (Rushton) turbine impeller in the vessel axis. Motion of the liquid is then superimposed with that of the bubbles in a still environment (ascending motion). The computation of the simulation includes determination of the spatial distribution of the gas holds-up (volumetric concentrations) in the agitated charge as well as of the total gas hold-up system depending on the impeller size and its frequency of revolutions, on the volumetric gas flow rate and the physical properties of gas and liquid. As model parameters, both liquid velocity field and normal gas bubbles distribution characteristics are considered, assuming that the bubbles in the system do not coalesce.

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On the automodel properties of the counter-current regurlarly stacked trickle bed columns

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19860295 ◽

1986 ◽

Vol 51 (2) ◽

pp. 295-301 ◽

Cited By ~ 2

Author(s):

Andrzej Gierczycki ◽

Vladimír Staněk ◽

Petr Vychodil ◽

Vladimír Jiřičný ◽

Jerzy Pikoń ◽

...

Keyword(s):

German Democratic Republic ◽

Democratic Republic ◽

Liquid Velocity ◽

Empirical Correlations ◽

Hydrodynamic Behaviour ◽

Trickle Bed ◽

Counter Current

An approach utilizing the automodel properties in describing the hydrodynamic behaviour of counter-current columns has been extended to regularly stacked beds. Two new kinds of the packing have been investigated: The so-called K-packing, developed in the German Democratic Republic and the Cellular packing, developed in Poland. The results of experiments have been presented in the form of plots of the normalized liquid hold-up, hp, versus the normalized liquid velocity, Ql, and two empirical correlations. A comparison with previous results with randomly packed counter-current trickle bed columns has also been made.

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Stability of a Viscous Liquid Jet in a Coaxial Twisting Compressible Airflow

Processes ◽

10.3390/pr9060918 ◽

2021 ◽

Vol 9 (6) ◽

pp. 918

Author(s):

Li-Mei Guo ◽

Ming Lü ◽

Zhi Ning

Keyword(s):

Viscous Liquid ◽

Axial Velocity ◽

Liquid Velocity ◽

Velocity Ratio ◽

Dominant Mode ◽

Liquid Jet ◽

Axisymmetric Mode ◽

Jet Instability ◽

Jet Stability ◽

Jet Breakup

Based on the linear stability analysis, a mathematical model for the stability of a viscous liquid jet in a coaxial twisting compressible airflow has been developed. It takes into account the twist and compressibility of the surrounding airflow, the viscosity of the liquid jet, and the cavitation bubbles within the liquid jet. Then, the effects of aerodynamics caused by the gas–liquid velocity difference on the jet stability are analyzed. The results show that under the airflow ejecting effect, the jet instability decreases first and then increases with the increase of the airflow axial velocity. When the gas–liquid velocity ratio A = 1, the jet is the most stable. When the gas–liquid velocity ratio A > 2, this is meaningful for the jet breakup compared with A = 0 (no air axial velocity). When the surrounding airflow swirls, the airflow rotation strength E will change the jet dominant mode. E has a stabilizing effect on the liquid jet under the axisymmetric mode, while E is conducive to jet instability under the asymmetry mode. The maximum disturbance growth rate of the liquid jet also decreases first and then increases with the increase of E. The liquid jet is the most stable when E = 0.65, and the jet starts to become more easier to breakup when E = 0.8425 compared with E = 0 (no swirling air). When the surrounding airflow twists (air moves in both axial and circumferential directions), given the axial velocity to change the circumferential velocity of the surrounding airflow, it is not conducive to the jet breakup, regardless of the axisymmetric disturbance or asymmetry disturbance.

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Heat Transmission Reinforcers Induced by MHD Hybrid Nanoparticles for Water/Water-EG Flowing over a Cylinder

Coatings ◽

10.3390/coatings11060623 ◽

2021 ◽

Vol 11 (6) ◽

pp. 623

Author(s):

Firas A. Alwawi ◽

Mohammed Z. Swalmeh ◽

Amjad S. Qazaq ◽

Ruwaidiah Idris

Keyword(s):

Heat Transfer ◽

Heat Transfer Rate ◽

Transfer Rate ◽

Volume Fraction ◽

Liquid Velocity ◽

Flow Characteristics ◽

Hybrid Nanoparticles ◽

Critical Parameters ◽

Heat Transmission ◽

Constant Wall Temperature

The assumptions that form our focus in this study are water or water-ethylene glycol flowing around a horizontal cylinder, containing hybrid nanoparticles, affected by a magnetic force, and under a constant wall temperature, in addition to considering free convection. The Tiwari–Das model is employed to highlight the influence of the nanoparticles volume fraction on the flow characteristics. A numerical approximate technique called the Keller box method is implemented to obtain a solution to the physical model. The effects of some critical parameters related to heat transmission are also graphically examined and analyzed. The increase in the nanoparticle volume fraction increases the heat transfer rate and liquid velocity; the strength of the magnetic field has an adverse effect on liquid velocity, heat transfer, and skin friction. We find that cobalt nanoparticles provide more efficient support for the heat transfer rate of aluminum oxide than aluminum nanoparticles.

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Model investigations on liquid velocity induced by submerged gas injection in steel bath

Steel Research ◽

10.1002/srin.198801545 ◽

1988 ◽

Vol 59 (11) ◽

pp. 484-491 ◽

Cited By ~ 7

Author(s):

Satish C. Koria

Keyword(s):

Liquid Velocity ◽

Gas Injection

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Study of Flow Boiling Characteristics of a Microchannel Using High Speed Visualization

Journal of Heat Transfer ◽

10.1115/1.4023879 ◽

2013 ◽

Vol 135 (8) ◽

Cited By ~ 3

Author(s):

Rashid Ali ◽

Björn Palm ◽

Claudi Martin-Callizo ◽

Mohammad H. Maqbool

Keyword(s):

Heat Flux ◽

Flow Pattern ◽

Indium Tin Oxide ◽

High Speed ◽

Liquid Velocity ◽

Flow Boiling ◽

Fused Silica ◽

Internal Diameter ◽

Electrically Conductive ◽

Heated Length

This paper presents the visualization results obtained for an experimental study of R134a during flow boiling in a horizontal microchannel. The microchannel used was a fused silica tube having an internal diameter of 781 μm, a heated length of 191 mm, and was coated with a thin, transparent, and electrically conductive layer of indium-tin-oxide (ITO) on the outer surface. The operating parameters during the experiments were: mass flux 100–400 kg/m2 s, heat flux 5–45 kW/m2, saturation temperatures 25 and 30 °C, corresponding to saturation pressures of 6.65 bar and 7.70 bar and reduced pressures of 0.163 and 0.189, respectively. A high speed camera with a close up lens was used to capture the flow patterns that evolved along the channel. Flow pattern maps are presented in terms of the superficial gas and liquid velocity and in terms of the Reynolds number and vapor quality plots. The results are compared with some flow pattern maps for conventional and micro scale channels available in the literature. Rigorous boiling and increased coalescence rates were observed with an increase in the heat flux.

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Effects of Gas and Liquid Velocity on Steady-State Foam Flow at High Temperature

10.2118/24179-ms ◽

1992 ◽

Cited By ~ 61

Author(s):

W.T. Osterloh ◽

M.J. Jante

Keyword(s):

Steady State ◽

High Temperature ◽

Liquid Velocity ◽

Foam Flow

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Performance of Corrosion Inhibitors at High CO2 Pressures

2008 7th International Pipeline Conference, Volume 2 ◽

10.1115/ipc2008-64114 ◽

2008 ◽

Author(s):

Patchareeporn Sintoorahat ◽

Aree Wairatpanich ◽

Suchada Chimam ◽

Dayin Mongkholkhajornsilp ◽

Cheolho Kang

Keyword(s):

Corrosion Inhibitors ◽

Liquid Velocity ◽

Flow Characteristics ◽

Stratified Flow ◽

Inhibitor Concentration ◽

Flow Loop ◽

Corrosion Rates ◽

Offshore Pipeline ◽

Carbon Dioxide Pressure ◽

Corrosion Rate Measurement

The objective of this study was to evaluate the performance of two corrosion inhibitors (CI-A and CI-B) under conditions similar to the second PTT’s offshore pipeline. The experiments were carried out in flow-loop system, 36 m long, 10.16 cm diameter at 10.5 and 14 bar of carbon dioxide pressure, a temperature at 50°C. The performances of corrosion inhibitors were examined under conditions of superficial liquid velocity of 0.03 m/s and gas velocities of 6, 8 and 10 m/s in 0 and 3 degree inclinations using the ER probe and X65 weight-loss coupons for corrosion rate measurement at the top and bottom of pipe. According to flow characteristics, it was found that the smooth and wavy stratified flow occurred in 0 degree. For 3 degree inclination, wavy stratified flow with big waves was dominantly presented for all conditions. Corrosion inhibitor B showed a better performance than inhibitor A in all cases. For inhibitor B, the target corrosion rates of less than 0.1 mm/yr were achieved in all conditions with 50 ppm of inhibitor concentration whereas the amount of 75 ppm inhibitor concentration was required for CI-A. The color, turbidity, and emulsion tendency with corrosion inhibitors will be also discussed in this paper.

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Linear Instability Analysis of an Annular Swirling Viscous Liquid Jet

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.66-68.1556 ◽

2011 ◽

Vol 66-68 ◽

pp. 1556-1561 ◽

Cited By ~ 1

Author(s):

Kai Yan ◽

Ming Lv ◽

Zhi Ning ◽

Yun Chao Song

Keyword(s):

Viscous Liquid ◽

Liquid Velocity ◽

Aerodynamic Force ◽

Numerical Procedure ◽

Liquid Sheet ◽

Linear Instability ◽

Viscous Force ◽

Liquid Jet ◽

Instability Analysis ◽

Linear Instability Analysis

A three-dimensional linear instability analysis was carried out for an annular swirling viscous liquid jet with solid vortex swirl velocity profile. An analytical form of dispersion relation was derived and then solved by a direct numerical procedure. A parametric study was performed to explore the instability mechanisms that affect the maximum spatial growth rate. It is observed that the liquid swirl enhances the breakup of liquid sheet. The surface tension stabilizes the jet in the low velocity regime. The aerodynamic force intensifies the developing of disturbance and makes the jet unstable. Liquid viscous force holds back the growing of disturbance and the makes the jet stable, especially in high liquid velocity regime.

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