Scale process effect on the power consumption characteristics of a novel curved Rushton turbine within a reactor vessel

AbstractThe effects of baffling of an agitated vessel on the production of floating particles suspension are presented in this paper. Critical agitator speed, needed for particles dispersion in a liquid agitated in a vessel of the inner diameter of 0.295 m, was determined. The just drawdown agitator speeds were defined analogously to the Zwietering criterion. Specific agitation energy was calculated from the power consumption experimental data obtained by means of the strain gauge method. The experiments were carried out for twelve configurations of the baffles differing in number, length and their arrangement in the vessels. The following high-speed impellers were used: up- and downpumping six blade pitched blade turbines, Rushton turbine, and propeller. The impeller was located in the vessel in the height equal to two-thirds or one-third of the vessel diameter from the bottom of the vessel. The results were described in the form of a dimensionless equation.

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Effect of Baffle Length on Power Consumption in Turbulent Mixing Vessel with Rushton Turbine Impeller

KAGAKU KOGAKU RONBUNSHU ◽

10.1252/kakoronbunshu.37.147 ◽

2011 ◽

Vol 37 (2) ◽

pp. 147-149 ◽

Cited By ~ 2

Author(s):

Yoshihito Kato ◽

Noboru Kamei ◽

Yutaka Tada ◽

Azusa Nakaoka ◽

Yuichiro Nagatsu ◽

...

Keyword(s):

Power Consumption ◽

Turbulent Mixing ◽

Rushton Turbine ◽

Turbine Impeller

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The Effect of Experimental Conditions on Methane (95%)–Propane (5%) Hydrate Formation

Energies ◽

10.3390/en13246710 ◽

2020 ◽

Vol 13 (24) ◽

pp. 6710

Author(s):

Sotirios Nik. Longinos ◽

Mahmut Parlaktuna

Keyword(s):

Power Consumption ◽

Separation Factor ◽

Induction Time ◽

Hydrate Formation ◽

Equilibrium Line ◽

General View ◽

Experimental Conditions ◽

Rushton Turbine ◽

Pitched Blade Turbine

In the present study, the effect of different kinds of impellers with different baffles or no baffle was investigated. Up-pumping pitched blade turbine (PBTU) and Rushton turbine (RT) were the two types of impellers tested. The reactor was equipped with different designs of baffles: full, half and surface baffles or no baffles. Single (PBTU or RT) and dual (PBTU/PBTU or RT/RT) use of impellers with full (FB), half (HB), surface (SB) and no baffle (NB) combinations formed two sets of 16 experiments. There was estimation of rate of hydrate formation, induction time, hydrate productivity, overall power consumption, split fraction and separation factor. In both single and dual impellers, the results showed that RT experiments are better compared to PBTU in rate of hydrate formation. The induction time is almost the same since we are deep in the equilibrium line while hydrate productivity values are higher in PBTU compared to RT experiments. As general view RT experiments consume more energy compared to PBTU experiments.

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Agitation of a gas-solid-liquid system in a vessel with high-speed impeller and vertical tubular coil

Chemical Papers ◽

10.2478/s11696-012-0148-0 ◽

2012 ◽

Vol 66 (6) ◽

Cited By ~ 4

Author(s):

Marta Major-Godlewska ◽

Joanna Karcz

Keyword(s):

Power Consumption ◽

High Speed ◽

Gas Bubbles ◽

Liquid System ◽

Specific Power ◽

Specific Power Consumption ◽

Rushton Turbine ◽

Agitated Vessel ◽

Solids Concentration ◽

Solid Liquid

AbstractExperimental results of gas hold-up, power consumption and residence time of gas bubbles in a gas-solid-liquid system produced in an agitated vessel equipped with a high-speed impeller and a vertical tubular coil are presented in this paper. Critical agitator speed, needed for the dispersion of gas bubbles and solid particles in liquid were also identified. The studies were carried out in an agitated vessel of the inner diameter D = 0.634 m and the working liquid volume of about 0.2 m3. A tubular coil of the diameter of 0.7D, consisting of 24 vertical tubes of the diameter of 0.016D, was located inside the flat-bottomed vessel. The agitated vessel was equipped with a Rushton turbine with six blades or an A 315 impeller with four blades. Both impellers had diameter, d, equal to 0.33D. The vessel was filled with liquid up to the height H = D. In this study, air and particles of sea sand with the mean diameter of 335 μm and the concentration of up to 3.0 mass % were dispersed in distilled water as the liquid phase. The measurements were carried out within the turbulent regime of the fluid flow in the agitated vessel. Results of the measurements were processed graphically and mathematically. Lower values of the critical agitator speed, n JSG, needed for simultaneous dispersion of gas bubbles and particles with the solids concentration from 0.5 mass % to 2 mass %, were obtained for the vessel equipped with the A 315 impeller. Higher values of the specific power consumption were reached for the vessel with the Rushton turbine. Higher values of the gas hold-up and residence time of the gas bubbles in the fluid were obtained for the system equipped with the Rushton turbine. Results of the gas hold-up as a function of the specific power consumption, superficial gas velocity and solids concentration were approximated with good accuracy using Eq. (5).

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Hydrodynamic Characteristics of Mechanically Agitated Air - Aqueous Sucrose Solutions

Chemical and Process Engineering ◽

10.2478/cpe-2014-0007 ◽

2014 ◽

Vol 35 (1) ◽

pp. 97-107 ◽

Cited By ~ 5

Author(s):

Magdalena Cudak

Keyword(s):

Power Consumption ◽

High Speed ◽

Gas Flow ◽

Sucrose Concentration ◽

Empirical Relationship ◽

Experimental Studies ◽

Hydrodynamic Characteristics ◽

Dimensionless Numbers ◽

Rushton Turbine ◽

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)).

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Power Consumption of a Rushton Turbine Mixing Viscous Newtonian and Shear-thinning Fluids: Comparison between Experimental and Numerical Results

Chemical Engineering & Technology ◽

10.1002/(sici)1521-4125(199807)21:7<599::aid-ceat599>3.0.co;2-6 ◽

1998 ◽

Vol 21 (7) ◽

pp. 599-604 ◽

Cited By ~ 14

Author(s):

Claude Torrez ◽

Christophe André

Keyword(s):

Power Consumption ◽

Shear Thinning ◽

Numerical Results ◽

Rushton Turbine ◽

Shear Thinning Fluids

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Intensifying the Fermentation of Aspergillus oryzae in a Stirred Bioreactor Using Maxblend Impeller

The Open Chemical Engineering Journal ◽

10.2174/1874123101610010088 ◽

2016 ◽

Vol 10 (1) ◽

pp. 88-109 ◽

Cited By ~ 2

Author(s):

Narges Ghobadi ◽

Chiaki Ogino ◽

Naoto Ohmura

Keyword(s):

Growth Rate ◽

Enzyme Activity ◽

Power Consumption ◽

Aspergillus Oryzae ◽

Rushton Turbine ◽

Stirred Bioreactor ◽

Condition Effect ◽

Batch Condition ◽

Fermentation Parameters ◽

Stirred Bioreactors

Background: The intensification of fermentation in stirred bioreactors is an attractive approach for commercial interests and industries that work with biochemical products. Alpha amylase is an enzymatic bio-products that is produced largely from Aspergillus oryzae. Using adaptable agitator can be an efficient way for stirred fermentation. Objective: This study, concentrated on enhancing the mixing process in order to intensify Aspergillus oryzae fermentation. A straight type of Maxblend® impeller was used as an agitator to investigate the incubation parameters compared with the use of a 6-blade double Rushton turbine. Method: Stirred fermentation was done in batch condition. Effect of flow pattern of mixing on fermentation parameters was investigated after each sampling. Results: The results showed that the Maxblend® significantly intensified both enzyme activity and growth rate at low and moderate rates of power consumption (P). The main reason for the decreases in the growth rate and the enzyme activity during agitation by the Rushton turbine at low and high Pv was the lack of oxygen and mycelial damage, respectively. Additionally, use of the Maxblend® significantly intensified the KLa at low and moderate rates of power consumption. Conclusion: Axial and uniform mixing by Maxblend® impeller was resulted in improving the fermentation characteristics and enzyme activity.

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Power Consumption of Polymer Solutions in a Stirred Vessel Powered by an Hyperboloid Impeller

10.1115/imece2001/fed-24905 ◽

2001 ◽

Author(s):

Adélio S. Cavadas ◽

Fernando T. Pinho

Keyword(s):

Power Consumption ◽

Aqueous Solutions ◽

Xanthan Gum ◽

Polymer Solutions ◽

Reynolds Numbers ◽

Newtonian Fluids ◽

Solution Flow ◽

Stirred Vessel ◽

Concentrated Aqueous Solutions ◽

Rushton Turbine

Abstract Measurements of power consumption in stirred vessel flows powered by a Rushton and an hyperboloid impeller were carried out. The fluids were aqueous solutions of tylose, CMC and xanthan gum at weight concentrations ranging from 0.1% to 0.6% and also included Newtonian fluids. For the Rushton turbine flows the addition of polymer increased the Newton number by about 13–20% at Reynolds numbers in the range 1,000–3,000, whereas with the hyperboloid impeller the Newton number decreased about 13%. This decrease was especially noticeable for the CMC solutions and was absent from the 0.2% tylose solution flow. Concentrated aqueous solutions of CMC (5.2%) and XG (3.6%) were also produced to determine the characteristic impeller parameter k for the hyperboloid, following the procedure of Metzner and Otto (1957) which was found to be 48 ±16.

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