Distribution of Dynamic Pressure Along a Radial Baffle in an Agitated System with Standard Rushton Turbine Impeller

2001 ◽  
Vol 79 (8) ◽  
pp. 819-823 ◽  
Author(s):  
J. Kratěna ◽  
I. Fořt ◽  
O. Brůha ◽  
J. Pavel
Keyword(s):  
Dynamic Pressure ◽  
Rushton Turbine ◽  
Turbine Impeller

scholarly journals Dynamic Effect of Discharge Flow of a Rushton Turbine Impeller on a Radial Baffle

10.14311/198 ◽  
2001 ◽  
Vol 41 (1) ◽  
Author(s):  
J. Kratěna ◽  
I. Fořt ◽  
O. Brůha
Keyword(s):  
Dynamic Pressure ◽  
Dynamic Effect ◽  
Flow Region ◽  
Tangential Component ◽  
Turbulent Regime ◽  
Torsional Moment ◽  
Discharge Flow ◽  
Rushton Turbine ◽  
Dynamic Relation ◽  
Turbine Impeller

This paper presents an analysis of the mutual dynamic relation between the impeller discharge flow of a standard Rushton turbine impeller and a standard radial baffle at the wall of a cylindrical mixing vessel under turbulent regime of flow of an agitated liquid. A portion of the torsional moment of the baffle corresponding to the region of the force interaction of the impeller discharge stream and the baffle is calculated under the assumption of constant angular momentum in the flow region between the impeller and the baffles. This theoretically obtained quantity is compared with the torsional moment of the baffles calculated from the experimentally determined distribution of the peripheral (tangential) component of dynamic pressure along the height of the radial baffle in pilot plant mixing equipment. It follows from the results of our calculations that for both investigated impeller off-bottom clearances the theoretically determined transferred torsional moment of the baffles in the area of interference between the impeller discharge flow and the baffles agrees fairly well with experimentally determined data and, moreover, that more than 2/3 of the transferred torsional moment of the baffles as a whole is located in the above mentioned interference area.

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

2011 ◽  
Vol 37 (2) ◽  
pp. 147-149 ◽  
Author(s):  
Yoshihito Kato ◽  
Noboru Kamei ◽  
Yutaka Tada ◽  
Azusa Nakaoka ◽  
Yuichiro Nagatsu ◽  
...  
Keyword(s):  
Power Consumption ◽  
Turbulent Mixing ◽  
Rushton Turbine ◽  
Turbine Impeller

scholarly journals Structure of turbulent velocity field in the discharge stream from a standard Rushton turbine impeller

2017 ◽  
Vol 23 (2) ◽  
pp. 151-160 ◽  
Author(s):  
Bohus Kysela ◽  
Jiří Konfrst ◽  
Zdeněk Chára ◽  
Ivan Fořt
Keyword(s):  
Radial Direction ◽  
Laser Doppler Anemometry ◽  
Periodic Part ◽  
Spatial Distributions ◽  
Measurement Point ◽  
Rushton Turbine ◽  
Axial Profile ◽  
Similar Range ◽  
Turbulent Velocity Field ◽  
Turbine Impeller

The radial discharge jet from a standard Rushton turbine was investigated by the Laser Doppler Anemometry (LDA) method. Several distances from the impeller blades (in the radial direction) were chosen for the measurement of axial profiles: all three velocity components (radial, tangential and axial) were measured at each point of the axial profile. The obtained velocity time records were analysed and averaged results were decomposed into three parts: mean ensembleaverage, random and periodic. The ratio of the derived periodic part of the velocity was evaluated in each measurement point and for all velocity components. The obtained results indicate the regions where the periodic part of the velocity has significant effect and where the contribution of this part is almost negligible. Although the values of the periodic part of all velocity components have a rather similar range, the spatial distributions are different in the investigated region.

scholarly journals Power Input of High-Speed Rotary Impellers

10.14311/280 ◽  
2001 ◽  
Vol 41 (6) ◽  
Author(s):  
K. R. Beshay ◽  
J. Kratěna ◽  
I. Fořt ◽  
O. Brůha
Keyword(s):  
Pitch Angle ◽  
High Speed ◽  
Power Input ◽  
Cylindrical Vessel ◽  
Turbulent Regime ◽  
Power Dependence ◽  
Rushton Turbine ◽  
Weak Influence ◽  
Turbine Impeller ◽  
Blade Pitch Angle

This paper presents the results of an experimental investigation of the power input of pitched blade impellers and standard Rushton turbine impellers in a cylindrical vessel provided with four radial baffles at its wall under a turbulent regime of flow of an agitated liquid. The influence of the geometry of the pitched blade impellers (pitch angle, number of blades) and the off-bottom impeller clearance of both high-speed impellers tested on the impeller power input is determined in two sizes of the cylindrical vessel (0.3 m and 0.8 m diameter of vessel). A strain gauge torquemeter is used in the small vessel and a phase shift mechanical torquemeter is used in the large vessel. All results of the experiments correspond to the condition that the Reynolds number modified for the impeller exceeds ten thousand. The results of this study show that the significant influence of the separating disk thickness of the turbine impeller corresponds fairly well to the empirical equations presented in the literature. Both the influence of the number of impeller blades and the blade pitch angle of the pitched blade impeller were expressed quantitatively by means of the power dependence of the recently published correlations: the higher the pitch angle and the number of blades, the higher the values of the impeller power input. Finally, it follows from results of this study that the impeller off-bottom clearance has a weak influence on the power input of the Rushton turbine impeller, but with decreasing impeller off-bottom clearance the power input of the pitched blade impeller increases significantly.

scholarly journals Efficacy of partial baffles for a vessel agitated by a Rushton turbine impeller

2018 ◽  
Vol 24 (3) ◽  
pp. 293-301
Author(s):  
Masanori Yoshida ◽  
Kohei Ishioka ◽  
Hiromu Ebina ◽  
Koki Oiso ◽  
Hayato Shirosaki ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Flow Velocity ◽  
Liquid Flow ◽  
Energy Transmission ◽  
Discharge Flow ◽  
Rushton Turbine ◽  
Power Characteristics ◽  
Liquid Depth ◽  
Flow Through ◽  
Turbine Impeller

For a vessel agitated by a Rushton turbine impeller, the efficacy of partial baffles was evaluated through examination of the liquid flow and impeller power characteristics. The bulk flow formed a pattern having circulation loops of different intensity and largeness depending on the baffle condition: the baffle length relative to the liquid depth for the vessel. Consequently, the liquid flow within the vessel affected the impeller power number. The characteristic circulation loops, which generally reflect the baffle efficacy, were assessed in terms of the discharge flow through the impeller and the energy transmission within the vessel based on the flow velocity profiles. The shorter length of baffles fitted partially in the upper half of the liquid phase was revealed to be effective, supported in combination by a comparable discharge flow and a successful energy transmission.

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