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 ◽  
...  

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.

10.14311/198 ◽  
2001 ◽  
Vol 41 (1) ◽  
Author(s):  
J. Kratěna ◽  
I. Fořt ◽  
O. Brůha

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.


Author(s):  
Suman Debnath ◽  
Anirban Banik ◽  
Tarun Kanti Bandyopadhyay ◽  
Mrinmoy Majumder ◽  
Apu Kumar Saha

Author(s):  
Marcel Escudier

This chapter is concerned primarily with the flow of a compressible fluid through stationary and moving blading, for the most part using the analysis introduced in Chapter 11. The principles of dimensional analysis are applied to determine the appropriate non-dimensional parameters to characterise the performance of a turbomachine. The analysis of incompressible flow through a linear cascade of aerofoil-like blades is followed by the analysis of compressible flow. Velocity triangles for flow relative to blades, and Euler’s turbomachinery equation, are introduced to analyse flow through a rotor. The concepts introduced are applied to the analysis of an axial-turbomachine stage comprising a stator and a rotor, which applies to either a compressor or a turbine.


Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 701 ◽  
Author(s):  
Lei Guo ◽  
Xiaochun Wen ◽  
Qipeng Bao ◽  
Zhancheng Guo

An investigation was made on the super-gravity aided rheorefining process of recycled 7075 aluminum alloy in order to remove tramp elements. The separation temperatures in this study were selected as 609 °C, 617 °C and 625 °C. And the gravity coefficients were set as 400 G, 700 G, 1000 G. The finely distributed impurity inclusions will aggregate to the grain boundaries of Al-enriched phase during heat treatment. In the field of super-gravity, the liquid phase composed of tramp elements Zn, Cu, Mg et al. will flow through the gaps between solid Al-enriched grains and form into filtrate. Both the weight of filtrate and removal ratio of tramp element improved with the increase of gravity coefficient. The total removal ratio of tramp element decreased with the fall of temperature due to the flowability deterioration of liquid phase. The time for effective separation of liquid/solid phases with super-gravity can be restricted within 1 min.


2021 ◽  
Vol 11 (4) ◽  
pp. 1936
Author(s):  
Abdel-Hakim Bouzid

The accurate prediction of liquid leak rates in packing seals is an important step in the design of stuffing boxes, in order to comply with environmental protection laws and health and safety regulations regarding the release of toxic substances or fugitive emissions, such as those implemented by the Environmental Protection Agency (EPA) and the Technische Anleitung zur Reinhaltung der Luft (TA Luft). Most recent studies conducted on seals have concentrated on the prediction of gas flow, with little to no effort put toward predicting liquid flow. As a result, there is a need to simulate liquid flow through sealing materials in order to predict leakage into the outer boundary. Modelling of liquid flow through porous packing materials was addressed in this work. Characterization of their porous structure was determined to be a key parameter in the prediction of liquid flow through packing materials; the relationship between gland stress and leak rate was also acknowledged. The proposed methodology started by conducting experimental leak measurements with helium gas to characterize the number and size of capillaries. Liquid leak tests with water and kerosene were then conducted in order to validate the predictions. This study showed that liquid leak rates in packed stuffing boxes could be predicted with reasonable accuracy for low gland stresses. It was found that internal pressure and compression stress had an effect on leakage, as did the thickness change and the type of fluid. The measured leak rates were in the range of 0.062 to 5.7 mg/s for gases and 0.0013 and 5.5 mg/s for liquids.


1996 ◽  
Vol 21 (5) ◽  
pp. 347-356 ◽  
Author(s):  
V. Velidandla ◽  
S. Putta ◽  
R. P. Roy

Ultrasonics ◽  
1969 ◽  
Vol 7 (3) ◽  
pp. 195-196 ◽  
Author(s):  
H.V. Fairbanks ◽  
W.I. Chen

1976 ◽  
Vol 98 (3) ◽  
pp. 521-530 ◽  
Author(s):  
N. H. Kemp ◽  
H. Ohashi

Incompressible flow through an unstaggered cascade in general, unsteady, in-phase motion is considered. By methods of thin-airfoil theory, using the assumptions of wakes trailing back at the through-flow velocity, and the Kutta condition, exact analytical expressions are derived for loading, lift and moment. As application, harmonic motion is considered for plunging, pitching, and sinusoidal gusts. Numerical values of lift and moment for these three cases are given graphically (tables are available from the authors). The results show strong analogies with isolated unsteady thin-airfoil theory. They should prove useful as simple examples of unsteady effects in cascades, and as check cases for other approximate or purely numerical analyses.


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