Residence time distribution and Peclet number correlation for continuous oscillatory flow reactors

Slavnić, Danijela S.; Živković, Luka A.; Bjelić, Ana; Bugarski, Branko; Nikačević, Nikola M.

doi:10.1002/jctb.5242

Cited by 16 publications

(10 citation statements)

References 31 publications

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“…RTD experiments have been carried out previously in various setups of the oscillatory baffled flow equipment with internal diameters between 4 and 50 mm. − These assessments suggest that operating conditions ensuring near-plug flow operation can be achieved in these systems and that superior heat transfer can be obtained when using oscillatory baffled flow conditions when compared to no oscillation and/or no baffles present. Studies measuring axial dispersion in oscillatory flow systems have utilized a wide range of geometries and operating conditions, − and a summary of this literature can be found in the Supporting Information.…”

Section: Introductionmentioning

confidence: 99%

Heat Transfer and Residence Time Distribution in Plug Flow Continuous Oscillatory Baffled Crystallizers

et al. 2021

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Heat transfer coefficients in a continuous oscillatory baffled crystallizer (COBC) with a nominal internal diameter of 15 mm have been determined as a function of flow and oscillatory conditions typically used under processing conditions. Residence time distribution measurements show a near-plug flow with high Peclet numbers on the order of 100–1000 s, although there was significant oscillation damping in longer COBC setups. Very rapid heat transfer was found under typical conditions, with overall heat transfer coefficients on the order of 100 s W m–2 K–1. Furthermore, poor mixing in the COBC cooling jacket was observed when lower jacket flow rates were implemented in an attempt to decrease the rate of heat transfer in order to achieve more gradual temperature profile along the crystallizer length. Utilizing the experimentally determined overall heat transfer coefficients, a theoretical case study is presented to investigate the effects of the heat transfer rate on temperature and supersaturation profiles and to highlight potential fouling issues during a continuous plug flow cooling crystallization.

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Section: Introductionmentioning

confidence: 99%

Heat Transfer and Residence Time Distribution in Plug Flow Continuous Oscillatory Baffled Crystallizers

et al. 2021

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“…Flow rates resulting in Re n < 10 report that Re o has little impact on axial dispersion, with axial dispersion through baffled sectors increasing due to lack of transport along the reactor length . Furthermore, a minimum net oscillatory Reynolds number of 130 must be met to achieve near-plug-flow conditions alongside adequate mixing within a continuous OBR, which could incur very high velocity ratios at these ultralow flow rates. In a study conducted by Slavanić et al using low Re n , they found that when high x 0 and low f are used to reach a higher Re o , the fluid operates with low levels of axial dispersion and with adequate mixing, providing ψ > 1 .…”

Section: Resultsmentioning

confidence: 99%

“…42 Furthermore, a minimum net oscillatory Reynolds number of 130 must be met to achieve near-plug-flow conditions alongside adequate mixing within a continuous OBR, 53 which could incur very high velocity ratios at these ultralow flow rates. In a study conducted by Slavanićet al using low Re n , they found that when high x 0 and low f are used to reach a higher Re o , the fluid operates with low levels of axial dispersion and with adequate mixing, 53 providing ψ > 1. 54 The current research found a trend of higher TiS values at x 0 (8−12 mm) in the single-column experiments compared to values below 6 mm.…”

Section: Change Of Rtd Across the Reactor Lengthmentioning

confidence: 99%

Revisiting the Effect of U-Bends, Flow Parameters, and Feasibility for Scale-Up on Residence Time Distribution Curves for a Continuous Bioprocessing Oscillatory Baffled Flow Reactor

Cox

Salonitis

Rebrov

et al. 2022

Ind. Eng. Chem. Res.

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An oscillatory baffled flow reactor (OBR) has been designed with 60 interbaffled cells. The baffled columns of 40 mm internal diameter together result in a reactor length of 5740 mm. The oscillatory amplitude and frequency were in the range of 2−12 mm and 0.3−2 Hz, respectively. The report investigates the impact of Ubends and the number of reactor sections on axial dispersion for scaleup feasibility. A prediction model using operating parameters has been developed to maximize plug flow conditions using the tanks-in-series (TiS) model. The maximum TiS value was 13.38 in a single column compared to 43.68 in the full reactor at a velocity ratio of 2.27 using oscillatory parameters 8 mm and 0.3 Hz. The mixing efficiency along the reactor was found to decrease after each column at amplitudes <6 mm compared to amplitudes up to 12 mm, where a negligible impact was observed. U-bend geometry had a significant role in the decrease of TiS values.

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“…where v its velocity of the protoplasm. We have estimated the oscillatory (i.e., maximum) Reynolds number Re max [43] attained during protoplasmic flow in the strands of P. polycephalum using data directly available from our experiments and from literature. The maximum Reynolds number is obtained using the maximum velocity attained during shuttle streaming, which in our experiments was 1.20 mm s −1 (figure 2), [22], respectively.…”

Section: Laminar Flowmentioning

confidence: 99%

Effective mixing due to oscillatory laminar flow in tubular networks of plasmodial slime moulds

Haupt

Hauser

2020

New J. Phys.

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The plasmodium of the unicellular slime mould Physarum polycephalum forms an extended vascular network in which protoplasm is transported through the giant cell due to peristaltic pumping. The flow in the veins is always parabolic and it performs shuttle streaming, i.e., the flow reverses its direction periodically. However, particles suspended in the protoplasm are effectively and rapidly distributed within the cell. To elucidate how an effective mixing can be achieved in such a microfluidic system with Poiseuille flow, we performed micro-particle imaging velocimetry experiments and advected virtual tracers in the determined time-dependent flow fields. Two factors were found to be crucial for effective mixing: (i) flow splitting and flow reversals occurring at junctions of veins and (ii) small delays in the reversals of flows in the veins at a junction. These factors enhance the distribution of fluid volumes and hence promote mixing due to chaotic advection. From the residence time distributions of particles at a junction, it is estimated that about 10% of the volume is effectively redistributed at a junction during one period of the shuttle streaming. We presume that the principles of mixing unravelled in P. polycephalum represent a promising approach to achieve efficient mixing in man-made microfluidic devices. Figure 1. Network of tubular veins in the plasmodium of P. polycephalum strand HU195 × HU200. The cell extends and propagates to the right. The dense apical front (at the right) gives way to a vast network of tubular stands, where protoplasm is transported by peristalsis. Dimensions: 6.14 × 4.60 cm 2 .can be adapted to the situation in P. polycephalum. By contrast to linear veins, in branched hemo-dynamic flow networks, there are feedbacks between the local pressures generated by the contraction of the veins, the flow velocity of protoplasm, and the compliance of the veins (i.e., the increase in their diameter) [11]. This leads to phase shifts between the flows that emanate from (and lead to) a junction of veins.Several models have been put forward to describe the interplay between the cellular mechanics of the vein and the peristaltic flow [8,12,13]. These models all rely on a coupling between the underlying biochemical (driving) system, that is coupled to cell and fluid mechanics. These models have sparked a novel interest in studying the mechanical properties of P. polycephalum [14].The vein network of P. polycephalum forms regular graphs, i.e., graphs with a unique node degree k = 3 [1, 2]. The vein segments have different thicknesses and lengths [1,2] in order to provide for an optimized transport of protoplasm through the cell [15,16]. With respect to transport efficiency, the architecture of these networks is hierarchic and self-similar [16]. Furthermore, the networks are highly adaptive [1,2,15], and an originally dense network may coarsen with time [1,2,[15][16][17][18]. In the absence of any external cue, the contraction of the thicker veins is almost synchronous over the entire network [19], ...

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Residence time distribution and Peclet number correlation for continuous oscillatory flow reactors

Cited by 16 publications

References 31 publications

Heat Transfer and Residence Time Distribution in Plug Flow Continuous Oscillatory Baffled Crystallizers

Heat Transfer and Residence Time Distribution in Plug Flow Continuous Oscillatory Baffled Crystallizers

Revisiting the Effect of U-Bends, Flow Parameters, and Feasibility for Scale-Up on Residence Time Distribution Curves for a Continuous Bioprocessing Oscillatory Baffled Flow Reactor

Effective mixing due to oscillatory laminar flow in tubular networks of plasmodial slime moulds

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