Hydrodynamic Characteristics of Mechanically Agitated Air - Aqueous Sucrose Solutions

Abstract

The aim of the research presented in this paper was determination of power consumption and gas hold-up in mechanically agitated aerated aqueous low concentration sucrose solutions. Experimental studies were conducted in a vessel of diameter 0.634 m equipped with high-speed impellers (Rushton turbine, Smith turbine or A 315). The following operating parameters were changed: volumetric gas flow rate (expressed by superficial gas velocity), impeller speed, sucrose concentration and type of impeller. Based on the experiments results, impellers with a modified shape of blades, e.g. CD 6 or A 315, could be recommended for such gas-liquid systems. Power consumption was measured using strain gauge method. The results of gas holdup measurements have been approximated by an empirical relationship containing dimensionless numbers (Eq. (2)).

Power Input Measurements in Stirred Bioreactors at Laboratory Scale

“…2 (see Figure 4 , Figure 5 , Figure 6 ). The standard Rushton turbine was used as a reference with well documented power numbers in the literature 1 16 17 18 19 20 21 22 23 24 25 . As can be seen from Figure 4a , the power number in the smaller 2 L vessel (bioreactor #1) decreased at low Reynolds numbers (100 < Re < ≈500) from P 0 = 6.3 to P 0 ≈ 3.3 before it increased again above Re ≈ 2000.…”

“…stationary heat balance or dynamic heating through the agitation) or the torque upon the agitator. The latter can be experimentally determined by dynamometers, torque meters or strain gauges, which have been applied for a variety of agitators, including single or multi-stage Rushton turbines 1 16 17 18 19 20 21 22 23 24 25 , pitched blade impellers 19 20 23 26 27 , InterMig 19 21 and Scaba impellers 28 29 . A detailed review is provided by Ascanio et al (2004) 30 .…”

Power and mass exchange characteristics of a bioreactor equipped with disk perforated mixers

“…Однако технические характеристики мешалок данного типа исследованы недостаточно. В то же время известно, что мешалки с наклонными поверхностями имеют большую энергетическую эффективность по сравнению с турбиной Раштона [3]. Целью настоящей работы являлось получение экспериментальных зависимостей, отражающих связи между конструктивными и режимными параметрами аппаратов с дисковыми перфорированными мешалками.…”

Numerical analysis of momentum transfer processes in a mechanically agitated air – biophase – liquid system

“…Karcz and Kamińska-Brzoska (1994a,b) studied experimentally the influence of the geometrical parameters of the turbine with concave and convex blades on power consumption and heat transfer process in the liquid phase. Gas dispersion in the liquid phase in the agitated vessel equipped with a turbine disc impeller with curved blades was experimentally analysed by Cudak (2011Cudak ( , 2014; Musiał et al (2015); Rielly et al (1992); Sensel et al (1993); Smith and Katsanevakis (1993); Van't Riet et al (1976); Warmoeskerken and Smith (1989) and Zhengming et al (1991). Junker et al (2000) experimentally examined dual impeller combinations of CD 6 impeller in fermentation vessels.…”