Experimental characterization of axial dispersion in coiled flow inverters

Rossi, Damiano; Gargiulo, L; Valitov, Gleb; Gavriilidis, Asterios; Mazzei, Luca

doi:10.1016/j.cherd.2017.02.011

Cited by 60 publications

(44 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Increasing the linear velocity to up to 300 cm/hr (or 10.1 ml) has a limited impact on initial peak steepness (see Figure 2a), which highlights the flexibility and simplicity of operation of the packed bed CVIR. Such flexibility—the possibility to operate at either 1 or 60 min incubation time with narrow RTD—has not been demonstrated for reactors based on Dean vortices, possibly because narrow RTD is achieved for a limited range of Reynolds number, Dean number, and coil‐to tube diameter (Klutz et al, 2015; Parker et al, 2018; Rossi, Gargiulo, Valitov, Gavriilidis, & Mazzei, 2017). The HETP increased with increasing linear—this is expected as hydrodynamic dispersion dominates in this range of linear velocities (Carta & Jungbauer, 2010; the linear velocity range assessed—4.90–300 cm/hr—is equivalent to a reduced velocity range of 3.58–219 in the van Deemter plot).…”

Section: Resultsmentioning

confidence: 99%

Truly continuous low pH viral inactivation for biopharmaceutical process integration

Martins

Sencar

Hammerschmidt

et al. 2020

Biotech & Bioengineering

View full text Add to dashboard Cite

Continuous virus inactivation (VI) has received little attention in the efforts to realize fully continuous biomanufacturing in the future. Implementation of continuous VI must assure a specific minimum incubation time, typically 60 min. To guarantee the minimum incubation time, we implemented a packed bed continuous viral inactivation reactor (CVIR) with narrow residence time distribution (RTD) for low pH incubation. We show that the RTD does not broaden significantly over a wide range of linear flow velocities—which highlights the flexibility and robustness of the design. Prolonged exposure to acidic pH has no impact on bed stability, assuring constant RTD throughout long term operation. The suitability of the packed bed CVIR for low pH inactivation is shown with two industry‐standard model viruses, that is xenotropic murine leukemia virus and pseudorabies virus. Controls at neutral pH showed no system‐induced VI. At low pH, significant VI is observed, even after only 15 min. Based on the low pH inactivation kinetics, the continuous process is equivalent to traditional batch operation. This study establishes a concept for continuous low pH inactivation and, together with previous reports, highlights the versatility of the packed bed reactor for continuous VI, regardless of the inactivation method.

show abstract

Section: Resultsmentioning

confidence: 99%

Truly continuous low pH viral inactivation for biopharmaceutical process integration

Martins

Sencar

Hammerschmidt

et al. 2020

Biotech & Bioengineering

View full text Add to dashboard Cite

show abstract

“…In the last years, CFIs have been characterized in terms of mixing and residence time distribution [3][4][5][6][7][8][9] and were applied for various processes such as liquid-liquid extraction [10][11][12], precipitation [13], crystallization [14][15][16], and gas-liquid reactions [17][18][19]. Here, increased mass transfer in a CFI was observed compared to straight and helically coiled capillaries as well as a more narrow residence time distribution.…”

Section: Introductionmentioning

confidence: 99%

Kinetic Study of Leuco‐Indigo Carmine Oxidation and Investigation of Taylor and Dean Flow Superposition in a Coiled Flow Inverter

et al. 2019

View full text Add to dashboard Cite

In two‐phase capillary flow, Taylor and Dean vortices can enhance mass transfer according to recent studies. By utilizing a colorimetric method based on the consecutive oxidation of leuco‐indigo carmine it is possible to visualize the superposition of Taylor and Dean vortices in a gas‐liquid system. A kinetic study is performed in order to estimate the enhancement factor. Depending on the flow conditions, three different flow regimes are identified with different intensities of Taylor and Dean vortices affecting the oxygen distribution within the liquid phase. A dimensionless number is derived that describes this transition in flow regimes.

show abstract

“…These inversions promote better radial mixing, helping to lessen the impact of the stagnation points at the centres of the Dean vortices. [15] Coiled flow inverters have also been proposed as a method for enhancing heat transfer rates. For example, Singh & Nigam [16] recently reported the pilot scale results of three CFI heat exchangers, where the entire coil assemblies (stainless steel) were placed inside a shell.…”

Section: Introductionmentioning

confidence: 99%

Oscillatory fluid motion unlocks plug flow operation in helical tube reactors at lower Reynolds numbers (Re ≤ 10)

McDonough

Murta

Law

et al. 2019

Chemical Engineering Journal

View full text Add to dashboard Cite

Flow in helical tubes exhibits plug flow characteristics above a critical flow rate due to the formation of Dean vortices. In this study, we report the novel use of oscillatory flow inside coiled tubes to achieve high degrees of plug flow at lower flow rates. The plug flow enhancement appeared to 'switch-on' then 'switch-off' as the oscillation intensity was increased, corresponding to 'oscillatory Dean numbers' of Deo = 70-200, where secondary instabilities are expected. It is believed that oscillatory motion leads to the periodic formation and unravelling of Dean vortices. For a 5 mm tube diameter, the effects of radius of curvature (12.5-32.5 mm), tube pitch (7.5-12.5 mm), net flow rate (Ren = 10-50), oscillation frequency (2-8 Hz) and oscillation amplitude (1-8 mm) were studied. The prototype helical coil reactors were rapidly manufactured using 3D printing. The optimal conditions for plug flow corresponded to Deo/Ren = 2-8, at Strouhal numbers in the range St = 1-2. Plug flow was observed at net flow Reynolds numbers at least as low as Ren = 10, compared to Ren = 70-300 in the literature for coiled tubes subjected to steady flows.Graphical Abstract:

show abstract

Experimental characterization of axial dispersion in coiled flow inverters

Cited by 60 publications

References 44 publications

Truly continuous low pH viral inactivation for biopharmaceutical process integration

Truly continuous low pH viral inactivation for biopharmaceutical process integration

Kinetic Study of Leuco‐Indigo Carmine Oxidation and Investigation of Taylor and Dean Flow Superposition in a Coiled Flow Inverter

Oscillatory fluid motion unlocks plug flow operation in helical tube reactors at lower Reynolds numbers (Re ≤ 10)

Contact Info

Product

Resources

About

Experimental characterization of axial dispersion in coiled flow inverters

Cited by 60 publications

References 44 publications

Truly continuous low pH viral inactivation for biopharmaceutical process integration

Truly continuous low pH viral inactivation for biopharmaceutical process integration

Kinetic Study of Leuco‐Indigo Carmine Oxidation and Investigation of Taylor and Dean Flow Superposition in a Coiled Flow Inverter

Oscillatory fluid motion unlocks plug flow operation in helical tube reactors at lower Reynolds numbers (Re ≤ 10)

Contact Info

Product

Resources

About

Oscillatory fluid motion unlocks plug flow operation in helical tube reactors at lower Reynolds numbers (Re ≤ 10)