Rapid Determination of the Residence Time Distribution (RTD) Function in an Oscillatory Baffled Reactor (OBR) Using a Design of Experiments (DoE) Approach

Abbott, Matthew S.R.; Harvey, Adam P.; Morrison, Michelle I.

doi:10.1515/ijcre-2014-0040

Cited by 9 publications

(37 citation statements)

References 25 publications

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“…Concerning the characterisation of mixing quality, the main objectives of the previous work presented in the literature are to evaluate the plug flow behaviour via the residence time distribu tion (RTD) and to determine the operating conditions required to achieve the narrowest RTD (Abbott et al, 2014;Dickens et al, 1989;Kacker et al, 2017;Mackley and Ni, 1991;Reis et al, 2004). Most of these studies are experimental and have analysed the dispersion of a pulse injection of homogeneous tracer in the continuous phase as a function of the oscillatory and net flow con ditions, as well as the geometrical parameters of the COBR.…”

Section: Nomenclaturementioning

confidence: 99%

Mixing performance in continuous oscillatory baffled reactors

Avila

Fletcher

Poux

et al. 2020

Chemical Engineering Science

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Areal distribution of mixing intensityIn the current literature, there is limited information on the influence of operating parameters on spatial mixing quality and how a secondary feed should be introduced into continuous oscillatory baffled reac tors (COBR) to achieve good mixing quality. This work explores for the fi rst time the impact of the posi tion of a secondary feed (passive non reactive tracer) on spatial mixing performance in a COBR using transient laminar CFD simulations. Three theoretical feed positions are stuclied covering a range of net flow and oscillatory Reynolds numbers (Re,,.,= 6 27 /Re0 = 24 96), the range being chosen to ensure that the flow field remains two dimensional in ail cases. Macromixing is evaluated by analysing the spa tial uniformity of the tracer with the areal distribution method developed by Alberini et al. (2014a). Introduction of the secondary stream at the reactor wall or upstream of the edge of the first b affle greatly improves mixing quality due to the recirculation edclies, which assist radial mixing. However, introduc tion of the secondary feed at the centreline results in high axial dispersion with limited radial mixing. With an adequate introduction position, mixing quality typically increases with an increment in the velocity ratio. Nevertheless, if the net flow is too low, mixing performance decreases because the sec ondary stream is pushed upstream of the baffles, where it does not benefit from flow recirculation.

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Section: Nomenclaturementioning

confidence: 99%

Mixing performance in continuous oscillatory baffled reactors

Avila

Fletcher

Poux

et al. 2020

Chemical Engineering Science

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“…However, it should be noted that some other studies reported distinct results from those previously mentioned. For example, in the case of Abbott et al, 57 the axial dispersion reached its minimum at x 0 = 1.5−3 mm and f = 1.00−1.75 Hz; in the case of Howes and Mackley, 58 the axial dispersion reached its minimum at different values of Re o , depending on both St and Re (Re = ρDu/μ, where u is the superficial net flow velocity); in the case of Mackley and Ni,33 at fixed St, the axial dispersion was found to be relatively independent of Re o and Re; and in the case of Palma and Giudici, 59 at x 0 = 10−25 mm, the axial dispersion increased as f increased from 0 to 5 Hz, whereas at x 0 = 5 mm, the axial dispersion was practically not affected by f. Such a variety of results suggest that the optimum operating conditions probably depend on the geometry of the OFR and thus should be assessed case by case. Figure 16 also shows that t m is considerably higher for the solid tracer than for the liquid tracer.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

Mixing Performance of Planar Oscillatory Flow Reactors with Liquid Solutions and Solid Suspensions

Cruz

Silva

Rocha

et al. 2021

Ind. Eng. Chem. Res.

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The mixing performance of planar oscillatory flow reactors (planar-OFRs) with liquid solutions and solid suspensions was investigated. The planar-OFR is a relatively new variant of the OFR where the conventional sharp-edged periodic constrictions are replaced with smooth periodic constrictions and the conventional circular cross-section is replaced with a rectangular cross-section. The experimental results show that both the minimum mixing intensity required to fully suspend solids and the time required to reach a specific degree of concentration uniformity after injection of a liquid or solid tracer largely depend on the operating conditions, such as the frequency and amplitude of oscillation and the geometric parameters, such as the cell aspect ratio and the ratio of the open constriction area to the straight section area, in the planar-OFR.

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“…Two pH probes (Mettler Toledo LE407) with a measured response time of 10 s were connected 50 mm from the inlet and outlet of the reactor and controlled through an Arduino. Data were livestreamed into Excel using data streamer software at an interval of 1 s, with the value converted into a concentration of hydroxide ions, as in the study by Abbott et al 9 Each experiment was run until the pH returned to its starting value.…”

Section: Residence Time Distribution Experimental Setupmentioning

confidence: 99%

“…This range was selected based on current observations in the literature for maximizing plug-flow conditions and TiS values. 9,33 Re Re…”

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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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Rapid Determination of the Residence Time Distribution (RTD) Function in an Oscillatory Baffled Reactor (OBR) Using a Design of Experiments (DoE) Approach

Cited by 9 publications

References 25 publications

Mixing performance in continuous oscillatory baffled reactors

Mixing performance in continuous oscillatory baffled reactors

Mixing Performance of Planar Oscillatory Flow Reactors with Liquid Solutions and Solid Suspensions

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

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