Determination of the effective radial mass diffusivity in tubular reactors under non-Newtonian laminar flow using residence time distribution data

Dantas, Jorge Aliomar Trocoli Abdon; Pegoraro, Paula R.; Gut, Jorge Andrey Wilhelms

doi:10.1016/j.ijheatmasstransfer.2013.12.003

Cited by 11 publications

(17 citation statements)

References 7 publications

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“…An eccentric screw pump (Netzsch, Brazil) provides fluid flow and tested flow rates were 10, 20, 30, 40 and 50 L/h. Tested fluids were a 80/20(w/w) glycerin/water mixture (Newtonian) and a 1.0%(w/w) solution of carboxymethylcellulose (CMC), which is pseudoplastic (Dantas et al, 2014). Generalized Reynolds number for power law fluids in tubes was calculated according to Carezzato et al (2007).…”

Section: Methodsmentioning

confidence: 99%

“…Generalized Reynolds number for power law fluids in tubes was calculated according to Carezzato et al (2007). Physical properties of fluids were calculated at average temperature (Dantas et al, 2014).…”

Section: Methodsmentioning

confidence: 99%

“…where ct (z,r,t) is the tracer concentration (Dantas et al, 2014). A step experiment is considered, where the tracer continuously enters the vessel with ct = ct,0 and there is no tracer an t = 0 (initial condition).…”

Section: Mass Transfer Modelmentioning

confidence: 99%

“…Considering the uncertainty in the experimental data in Figure 3, it is not possible to identity different behaviors between the two fluids. (PeM): a) E-curves for log(PeM)  0.5; b) E-curves for log(PeM)  0.5 (Dantas et al, 2014). Figure 4 presents simulation results of the mass transfer model for a Newtonian fluid (n = 1) in the form of theoretical E-curves for the dispersion of a tracer.…”

Section: Mass Transfer Experimentsmentioning

confidence: 99%

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Effective Radial Diffusivities to Model Enhanced Mass and Heat Transfer in Laminar Flow Reactors

Dantas¹,

Morais²,

Gut³

2015

Anais Do XX Congresso Brasileiro De Engenharia Química

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-Main features of a laminar flow reactor (LFR) are streamline flow and parabolic velocity profile. Consequently, heating and cooling are difficult and there is a large spread in the residence time distribution (RTD). Enhanced heat and mass transfer can be found in coils or corrugated tubes or in the presence of wall roughness, curves, pipe fittings or mechanical vibration. Modeling these cases can be complex because of the induced secondary flow. Objective of this work is to introduce this enhanced transport in the LFR model by means of effective radial diffusivities of heat and mass. Model validation experiments were conducted in a LFR with high wall relative roughness and curves. RTD experiments were compared with model simulations of tracer dispersion to obtain the mass diffusivity. Heat transfer experiments provided the effective thermal diffusivity. Tested fluids were a glycerin/water mixture (Newtonian) and a CMC solution (pseudoplastic). Model was successfully adjusted and parameters were correlated with Reynolds number for flow.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Mass Transfer Modelmentioning

confidence: 99%

Section: Mass Transfer Experimentsmentioning

confidence: 99%

See 2 more Smart Citations

Effective Radial Diffusivities to Model Enhanced Mass and Heat Transfer in Laminar Flow Reactors

Dantas¹,

Morais²,

Gut³

2015

Anais Do XX Congresso Brasileiro De Engenharia Química

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“…An analogous approach was taken by Dantas et al (2014) to model mass dispersion in laminar flow tubular reactors. Dispersion inducing elements were assumed to increase the radial mass diffusivity in the reactor.…”

Section: Introductionmentioning

confidence: 99%

Determination of the Effective Radial Thermal Diffusivity for Evaluating Enhanced Heat Transfer in Tubes Under Non-Newtonian Laminar Flow

Morais

Gut

2015

Braz. J. Chem. Eng.

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-Enhanced heat transfer in tubes under laminar flow conditions can be found in coils or corrugated tubes or in the presence of high wall relative roughness, curves, pipe fittings or mechanical vibration. Modeling these cases can be complex because of the induced secondary flow. A modification of the Graetz problem for non-Newtonian power-law flow is proposed to take into account the augmented heat transfer by the introduction of an effective radial thermal diffusivity. The induced mixing was modeled as an increased radial heat transfer in a straight tube. Three experiments using a coiled tube and a tubular heat exchanger with high relative wall roughness are presented in order to show how this parameter can be obtained. Results were successfully correlated with Reynolds number. This approach can be useful for modeling laminar flow reactors (LFR) and tubular heat exchangers available in the chemical and food industries.

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Combination of axial dispersion and velocity profile in parallel tanks-in-series compartment model for prediction of residence time distribution in a wide range of non-ideal laminar flow regimes

Fazli-Abukheyli

Darvishi

2019

Chemical Engineering Science

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Determination of the effective radial mass diffusivity in tubular reactors under non-Newtonian laminar flow using residence time distribution data

Cited by 11 publications

References 7 publications

Effective Radial Diffusivities to Model Enhanced Mass and Heat Transfer in Laminar Flow Reactors

Effective Radial Diffusivities to Model Enhanced Mass and Heat Transfer in Laminar Flow Reactors

Determination of the Effective Radial Thermal Diffusivity for Evaluating Enhanced Heat Transfer in Tubes Under Non-Newtonian Laminar Flow

Combination of axial dispersion and velocity profile in parallel tanks-in-series compartment model for prediction of residence time distribution in a wide range of non-ideal laminar flow regimes

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