Modified airlift reactors: The helical flow promoters

Gluz, M. D.; Merchuk, José C.

doi:10.1016/0009-2509(96)00174-1

Cited by 24 publications

(21 citation statements)

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“…It has to be mentioned that the observed sedimentation was more like a stagnant zone due to the similar density of the liquid and solid phase. However, these results agree well with the measurements done by Gluz and Merchuk (1996), who made similar observations with particles of different densities. The results demonstrate that the ALR-HFP is especially suitable for three-phase gas-liquicholid systems with low-density particles.…”

Section: Fluidization Capacitysupporting

confidence: 92%

“…The average linear liquid velocity increased with increasing superficial gas velocity, and decreased slightly with increasing liquid viscosity, which has been observed by several other investigators (Chisti, 1989 Gluz and Merchuk (1996), who also measured vL in an ALR-HFP with both a tracer and a solid particle follower method in different two-phase systems. of interest for the biological applications examined in this work.…”

Section: Liquid Velocitysupporting

confidence: 81%

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Characterization of an airlift reactor with helical flow promoters

et al. 1999

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The helical flow promoter (HFP), inserted in the downcomer of an airlift reactor (ALR), generates a helical flow pattern in the circulating gasliquid (solid) mixture. Data on the fluidization capacity, gas holdup, liquid velocity and mass transfer rate for two-and three-phase systems with two different carboxymethylcellulose solutions collected in a 58 L ALR-HFP are presented and compared with those of common pneumatic reactors. Generally, an increasing solid concentration led to a slight decrease in gas holdup and liquid velocity but to a considerable decrease in mass transfer rates. Insertion of HFPs produced a significantly enhanced fluidization capacity of solid particles compared to the common systems.L'activateur d'ecoulement helicoidal (Helical Flow Promoter (HFP)) insere dans la colonne descendante d'un reacteur a air ascendant (ALR) donne un mode d'ecoulement helicoi'dal dans le melange circulant gaz-liquide (solide). Les donnees sur la capacite de fluidisation, la retention de gaz, la vitesse du liquide et la vitesse du transfert de matiere pour des systemes biphasiques et triphasiques avec deux solutions de carboxymethylcellulose differentes recueillies dans un ALR-HFP de 58 L, sont presentees et comparees aux donnees de reacteurs pneumatiques courants. En generale, une concentration accrue de solides entraine une Iegere baisse de la retention de gaz et de la vitesse du liquide mais une forte diminution des vitesses de transfert de matiere. L'insertion d'un HFP donne une capacite de fluidisation des particules solides nettement amelioree. comparativement aux systemes habituels.

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Section: Fluidization Capacitysupporting

confidence: 92%

Section: Liquid Velocitysupporting

confidence: 81%

Characterization of an airlift reactor with helical flow promoters

et al. 1999

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“…A static mixer is a device that changes significantly the fluid dynamics in the gas lift reactor and consists of a series of static baffles (e.g., helical flow promoter). The following effects of the static mixers have been described: enhanced capacity for fluidizing solid particles, decrease of critical gas flow rate, increased mass transfer rate, decreased circulation time, and increased shear stress (114)(115)(116).…”

Section: Reactor Design and Process Hygienementioning

confidence: 99%

Continuous Beer Fermentation Using Immobilized Yeast Cell Bioreactor Systems

Brányik

Vicente

Dostálek

et al. 2008

Biotechnol Progress

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Traditional beer fermentation and maturation processes use open fermentation and lager tanks. Although these vessels had previously been considered indispensable, during the past decades they were in many breweries replaced by large production units (cylindroconical tanks). These have proved to be successful, both providing operating advantages and ensuring the quality of the final beer. Another promising contemporary technology, namely, continuous beer fermentation using immobilized brewing yeast, by contrast, has found only a limited number of industrial applications. Continuous fermentation systems based on immobilized cell technology, albeit initially successful, were condemned to failure for several reasons. These include engineering problems (excess biomass and problems with CO(2) removal, optimization of operating conditions, clogging and channeling of the reactor), unbalanced beer flavor (altered cell physiology, cell aging), and unrealized cost advantages (carrier price, complex and unstable operation). However, recent development in reactor design and understanding of immobilized cell physiology, together with application of novel carrier materials, could provide a new stimulus to both research and application of this promising technology.

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“…The dependence of particle size on the mass transfer to the suspended solids has been studied (35,300,301).…”

Section: Three-phase Alrsmentioning

confidence: 99%

“…The strengthening of this advantage was the aim of another modification, the helical flow promoter (HFP), proposed by Gluz and Merchuk (300). The HFP causes the fluid to flow down in the downcomer in a helical pattern (Fig.…”

Section: Alrs Using Mechanically Moved Internalsmentioning

confidence: 99%

Bioreactors: Airlift Reactors

Merchuk

Camacho

2010

Encyclopedia of Industrial Biotechnology

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ALRs are popular in modern bioprocess research and development and, in many cases, they have found industrial uses. The distinctive characteristics of ALRs are conferred by the fluid dynamics of the liquid‐gas or liquid gas‐solid mixtures: holdup, liquid velocity, and mixing in the riser, gas separator, and downcomer. Only a correct understanding of the interconnection of these regions can make possible the scale‐up of a laboratory device, to pilot or industrial size. Several correlations are available in the literature for the prediction of the fluid dynamic characteristics of the reactor and of the mass and heat transfer coefficients, and a selection is presented in this review. Significant progress has been made in the application of modern computational tools to the simulation and design of ALRs. In parallel, innovative and sophisticated methods have been applied to obtain a deeper insight into the mechanisms of fluid motion and the flow patterns in the reactor. However, no single research group has managed to cover all the variables over a wide range. The engineer confronting scale‐up or de novo design of an ALR must analyze the validity of the correlations and computation methods used for the calculations.

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Modified airlift reactors: The helical flow promoters

Cited by 24 publications

References 0 publications

Characterization of an airlift reactor with helical flow promoters

Characterization of an airlift reactor with helical flow promoters

Continuous Beer Fermentation Using Immobilized Yeast Cell Bioreactor Systems

Bioreactors: Airlift Reactors

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