Three-phase airlift internal loop reactor: correlations for predicting the main fluid dynamic parameters

AbstractThe effect of the biomass presence on the overall circulation velocity, the linear velocities both in the riser and the downcomer and the overall gas hold-up was studied in a three-phase internal loop airlift reactor (ILALR). The measured data were compared with those obtained using a two-phase system (air—water). All experiments were carried out in a 40 dm3 ILALR at six different biomass concentrations (ranging from 0 g dm−3 to 7.5 g dm−3), at a temperature of 30°C, under atmospheric pressure. Air and water were used as the gas and liquid model media, respectively. Pellets of Aspergillus niger produced during the fermentation of glucose to gluconic acid in the ILALR were considered solid phase. In addition, liquid velocities were measured during the fermentation of glucose to gluconic acid using Aspergillus niger. All measurements were performed in a bubble circulation regime. At given experimental conditions the effect of the biomass on the circulation velocities in the ILALR was negligible. However, increasing of the biomass concentration led to lower values of the total gas hold-up.

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Incidence of Posterior Capsular Opacification Based on Low and High Fluid-dynamic Parameters

Journal of the Korean Ophthalmological Society ◽

10.3341/jkos.2016.57.10.1555 ◽

2016 ◽

Vol 57 (10) ◽

pp. 1555

Author(s):

Yun Hyup Na ◽

Joo Youn Shin ◽

Jong Hyun Lee ◽

Jin Hyoung Kim ◽

Do Hyung Lee

Keyword(s):

Fluid Dynamic ◽

Posterior Capsular Opacification ◽

Dynamic Parameters ◽

High Fluid

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Latex Carpet Compound Rheology

Applied Rheology ◽

10.1515/arh-2008-0023 ◽

2008 ◽

Vol 18 (6) ◽

pp. 64250-1-64250-9

Author(s):

Nick Triantafillopoulos ◽

Bruce Schreiner ◽

James Vaughn ◽

Douglas Bousfield

Keyword(s):

Shear Rate ◽

Fluid Dynamic ◽

Pressure Distributions ◽

Time Period ◽

Three Phase ◽

Transient Viscosity ◽

Short Time ◽

Rate Development ◽

Solid System ◽

Foam Rheology

Abstract This is a study of three-phase foam rheology to qualify penetration in to backing webs during frothed carpet compounds applications. Transient viscosity as a function of shear rate under a short time period is proposed to characterize flow of these compounds in response to a rapidly changing shear field during their application. We developed a fluid dynamic model that predicts the shear and pressure distributions in the compound during its processing in a metering nip based on process parameters and rheological results. We tested frothed compound formulations that are empirically known to be “penetrating” and “non-penetrating” based on the choice of soap (frothing surfactant). Formulated at the same froth density, penetrating to carpet backing compounds had large froth bubbles, relatively low transient shear viscosity and showed increasing foam breakdown due to shear when compared to non-penetrating compounds. Such frothed compounds readily collapse under shear and have relatively low dynamic stability, so the transition from a three-phased (air/aqueous/solid) to a two-phased (water/solid) system occurs much easier and faster during application. The model predicts the shear rate development and a small difference in the pressure distributions in the applicator nip between these formulations, but reduction in drainage for the non-penetrating formulation.

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