Hydrodynamics of TBC with non-Newtonian liquids: Liquid holdup

Abukhalifeh, Hadil; Fayed, Muhammad E.; Dhib, Ramdhane

doi:10.1016/j.cep.2009.04.007

Cited by 6 publications

(5 citation statements)

References 14 publications

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“…Abukhalifeh et al investigated the experimental methodology and rheological properties of the CMC, and verified the TBC reliability. The study reveals the existence of three hydrodynamic stages and investigates the liquid holdup, static bed heights, liquid flow rates as well as superficial gas velocities of non‐Newtonian solutions made up with different CMC concentrations.…”

Section: Methodsmentioning

confidence: 93%

“…It was experimentally concluded that the apparent viscosity of the CMC solutions exhibit a shear-thinning behaviour of a non-Newtonian pseudo-plastic fluid, which implies that the viscosity decreases as the shear rates or the flow increases. [11] Figure 3 shows that the net pressure drop increases almost linearly with the liquid flow rates, for a given constant CMC concentration. A polynomial fit of the data was done to show the trend of its variation.…”

Section: Net Pressure Dropmentioning

confidence: 93%

“…In a previous study, Abukhalifeh et al [11] demonstrated that the net pressure drop rises with gas velocity and reaches a maximum point in the fixed bed region. Then, it drops slightly in the partial fluidised region, and finally it levels off to almost an invariant plateau during fully fluidised state.…”

Section: Net Pressure Dropmentioning

confidence: 94%

“…In addition, the effects of gas and liquid flow rates, relative static bed height, and particle properties were inspected at different rheological parameters . In a previous paper, Abukhalifeh et al discussed the impact of non‐Newtonian CMC solutions on the liquid holdup in the TBC tower. This study presents the net pressure drop and minimum fluidisation velocity in the TBC column using non‐Newtonian CMC solutions.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Hydrodynamics of turbulent bed contactor with non‐Newtonian liquids: Net pressure drop and minimum fluidisation velocity (part 2)

Abukhalifeh¹,

Fayed

Bhagat

et al. 2013

Can J Chem Eng

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The study investigates the hydrodynamic behaviour of non‐Newtonian liquids under different operating conditions in a turbulent bed contactor (TBC). Hollow plastic spheres were fluidised in an air stream flowing counter currently to an aqueous solution of carboxy methyl cellulose (CMC) of an apparent viscosity ranging from 5 to 25 mPa s. A set of experiments was carried out to investigate the net pressure drop and minimum fluidisation velocity of the process. The column was operated at different superficial gas velocities, liquid flow rates, CMC solution concentrations and static bed heights. Results show that the net pressure drop is independent of the superficial gas velocity, but it increases steadily with liquid flow rate and static bed height. However, it remains almost invariant with a relatively low CMC concentration (0.2–0.4 wt%), and it augments gradually as the CMC percent exceeds the threshold of 0.4 wt% which corresponds to a more viscous liquid solution. The minimum fluidisation velocity decreases with a CMC concentration lower than 0.5 wt% approximately, but increases as the CMC percent exceeds 0.5 wt%. The study presents a new insight on the behaviour of non‐Newtonian solutions in TBC columns.

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Section: Methodsmentioning

confidence: 93%

Section: Net Pressure Dropmentioning

confidence: 93%

Section: Net Pressure Dropmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Hydrodynamics of turbulent bed contactor with non‐Newtonian liquids: Net pressure drop and minimum fluidisation velocity (part 2)

Abukhalifeh¹,

Fayed

Bhagat

et al. 2013

Can J Chem Eng

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“…However, these studies are restricted to Newtonian liquids. Abukhalifeh et al (2009) studied the effect of viscosity of the liquid on the hydrodynamics of TBC and observed that the liquid viscosity variations had various impacts on the contactor parameters such as fluidisation velocity, pressure drop, liquid holdup, gas holdup and particle behaviour. There is no reported information in the literature on the hydrodynamics and flow regimes aspects of TBC for non-Newtonian conditions, even though in practice, there are a number of fluidised beds operating with non-Newtonian liquids in food, polymer processing and biotechnology.…”

Section: Introductionmentioning

confidence: 99%

Hydrodynamics and flow regimes in turbulent bed contactor with non‐Newtonian liquids

et al. 2011

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The flow regimes normally encountered in a turbulent bed contactor (TBC) are static, partially fluidised, completely fluidised and flooding regimes. Experiments were conducted in a TBC operating in Type I mode to identify the flow regimes with non-Newtonian liquid. Flow regime transition velocities were obtained from the pressure drop and bed expansion measurements at various operating and geometric variables. The variables include apparent viscosity of the liquid, gas and liquid velocities, size and density of the particles, and static bed height. The effect of the above variables on delineation of flow regime transition was studied. Based on the experimental data, correlations were proposed for predicting the transition velocity from one regime to the other. The influence of the variables on regime transition velocities is more or less similar to that observed for Newtonian liquids.

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Empirical models for the hydrodynamics of turbulent bed contactor with non-Newtonian liquids: (part 3)

Khalifeh

Madhuranthakam

Dhib

2019

Chemical Engineering Communications

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Hydrodynamics of TBC with non-Newtonian liquids: Liquid holdup

Cited by 6 publications

References 14 publications

Hydrodynamics of turbulent bed contactor with non‐Newtonian liquids: Net pressure drop and minimum fluidisation velocity (part 2)

Hydrodynamics of turbulent bed contactor with non‐Newtonian liquids: Net pressure drop and minimum fluidisation velocity (part 2)

Hydrodynamics and flow regimes in turbulent bed contactor with non‐Newtonian liquids

Empirical models for the hydrodynamics of turbulent bed contactor with non-Newtonian liquids: (part 3)

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