Study the effect of dense internals on the liquid velocity field and turbulent parameters in bubble column for Fischer–Tropsch (FT) synthesis by using Radioactive Particle Tracking (RPT) technique

Mesfer, Mohammed K. Al; Sultan, Abbas J.; Al‐Dahhan, Muthanna H.

doi:10.1016/j.ces.2016.12.001

Cited by 40 publications

(28 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These observations reveal that the internals redistribute the turbulent kinetic energy in each scale and the portion arising from large‐scale structures becomes more important. Actually, the total turbulent kinetic energy decreases in the presence of internals, as also observed in experiments in literature 22–24,50 . Moreover, the symmetry of distribution deteriorates in the column with internals, as also shown in Figure 10, particularly in the presence of 20% internals.…”

Section: Resultssupporting

confidence: 80%

See 1 more Smart Citation

Bubble size distribution in a bubble column with vertical tube internals: Experiments and CFD‐PBM simulations

Guan

Yang

2022

AIChE Journal

View full text Add to dashboard Cite

Knowledge of bubble size distribution (BSD) is critical for controlling mass transfer and reaction in bubble column reactors. Installation of internals further complicates this issue. The effects of internals on BSD were systematically investigated through experiments and computational fluid dynamics-population balance model simulations. The experiments show a bimodal distribution of the volume-based BSD except at low superficial gas velocity of 0.01 m/s. Addition of 20% internals increases the small-bubbles fraction, making the first BSD peak more evident. Correspondingly, the simulation reveals a prominent decrease of turbulent dissipation rate and turbulent kinetic energy. Moreover, while the unresolved turbulent kinetic energy dominates in the empty columns, the resolved portion becomes the major component in the presence of internals. This suggests that internals may redistribute turbulent kinetic energy in each scale, which provides more insights into the complex flow characteristics in the presence of internals and process intensification.

show abstract

Section: Resultssupporting

confidence: 80%

“…Actually, the total turbulent kinetic energy decreases in the presence of internals, as also observed in experiments in literature. [22][23][24]50 Moreover, the symmetry of distribution deteriorates in the column with internals, as also shown in Figure 10, particularly in the presence of 20% internals.…”

Section: Turbulencementioning

confidence: 63%

Bubble size distribution in a bubble column with vertical tube internals: Experiments and CFD‐PBM simulations

Guan

Yang

2022

AIChE Journal

View full text Add to dashboard Cite

show abstract

“…Many researchers have applied this method. [18][19][20][21][22][23][24][25] Its disadvantages are that it needs an extensive calibration and does not consider the impact of the angle between the tracer and a horizontal axis through the centre of the scintillation detector.…”

Section: Tracking Methods For Agglomerates In Fluidized Bedsmentioning

confidence: 99%

Behaviour of agglomerates formed by liquid injection in fluidized beds

et al. 2021

View full text Add to dashboard Cite

Formation of agglomerates in fluidized beds can cause operating problems, such as excessive stripper shed fouling, which can lead to premature unit shut down. The focus of this study is to reach a better understanding of how agglomerates move through a fluidized bed to improve the Fluid Cokers and minimize the risk of agglomerates reaching regions where they cause problems. Two experimental methods were used: first, a Gum Arabic binder solution was injected into a two-dimensional (2D) fluidized bed under conditions that simulate agglomerate formation in Fluid Cokers, and the mass and density of recovered agglomerates were measured; second, a new 2D radioactive particle tracking (RPT) method was developed to track the motion of model agglomerates. The fluidized bed had a steel wall, resulting in significant and non-uniform radiation absorption. The 2D RPT system was, thus, calibrated by placing the source at 290 locations in the bed, for each fluidization velocity. Since bubble flow patterns greatly affect agglomerate motion and segregation, a tribo-electric method was used to determine bubble flow distribution in the fluidized bed. The RPT and liquid injection methods gave similar vertical distributions of agglomerates. The main results were that increasing the fluidization velocity reduced segregation, and larger agglomerates were more likely to segregate. There was a strong correlation between the bubbles and agglomerates flow patterns: establishing an asymmetric flow pattern by injecting more fluidization gas in one side of the bed greatly reduced agglomerate segregation.

show abstract

“…Radioisotope-based measurement techniques have found many applications in different sectors of industry as well as in research and development. The radioisotopes measurement techniques have contributed to a wide range of process industries such as monitoring, inspection, process troubleshooting, optimization, control, and many other purposes [ 1 ]. An example of that can be found in petrochemical industry, where such techniques are very effective in monitoring and mapping the most multiphase flow systems of industrial interest.…”

Section: Introductionmentioning

confidence: 99%

“…Finally, the output of the reconstruction process is the Lagrangian time-series data of the tracer (i.e., time differentiation of instantaneous position). Consequently, the obtained Lagrangian time-series data provide abundant information about the tracked phase flow fields such as the 3D mean velocity fields, shear stresses, turbulence parameters, and dispersion coefficients, along with other parameters that depict characteristics and flow regimes and of the tagged flow phase [ 1 ]. As mentioned previously, the RPT is not ready-made technique and, hence, needs customize implementation to suit the investigated multiphase flow system and to obtain reliable data.…”

Section: Introductionmentioning

confidence: 99%

GEANT4 Simulation for Radioactive Particle Tracking (RPT) Technique

Alghamdi

Al-Juwaya

Alomari

et al. 2022

Sensors

Self Cite

View full text Add to dashboard Cite

In the past two decades, the radioactive particle tracking (RPT) measurement technique has been proven to visualize flow fields of most multiphase flow systems of industrial interest. The accuracy of RPT, and hence the data obtained, depend largely on the calibration process, which stands here as a basis for two subsequent processes: tracking and reconstruction. However, limitations in the RPT calibration process can be found in different experimental constrains and in assumptions made in the classical Monte Carlo approach used to simulate number of counts received by the detectors. Therefore, in this work, we applied a GEANT4-based Monte Carlo code to simulate the RPT calibration process for an investigated multiphase flow system (i.e., gas–liquid bubble column). The GEANT4 code was performed to simulate the number of counts received by 28 scintillation detectors for 931 known tracer positions while capturing all the types of photon interaction and overcoming solids’ angle limitations in classical approaches. The results of the simulation were validated against experimental data obtained using an automated RPT calibration device. The results showed a good agreement between the simulated and experimental counts, where the maximum absolute average relative deviation detected was about 5%. The GEANT4 model typically predicted the number of counts received by all the detectors; however, it over-estimated the counts when the number of primary events applied in the model was not the optimal.

show abstract

Study the effect of dense internals on the liquid velocity field and turbulent parameters in bubble column for Fischer–Tropsch (FT) synthesis by using Radioactive Particle Tracking (RPT) technique

Cited by 40 publications

References 36 publications

Bubble size distribution in a bubble column with vertical tube internals: Experiments and CFD‐PBM simulations

Bubble size distribution in a bubble column with vertical tube internals: Experiments and CFD‐PBM simulations

Behaviour of agglomerates formed by liquid injection in fluidized beds

GEANT4 Simulation for Radioactive Particle Tracking (RPT) Technique

Contact Info

Product

Resources

About