Numerical Simulation of the Laminar Flow Field and Mixing Time in Stirred Tank with Double Layer Impeller

2015 ◽  
Vol 51 (16) ◽  
pp. 185 ◽  
Author(s):  
Yingna LIANG
2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Koji Takahashi ◽  
Yoshiharu Sugo ◽  
Yasuyuki Takahata ◽  
Hitoshi Sekine ◽  
Masayuki Nakamura

The mixing performance in a vessel agitated by an impeller that inclined itself, which is considered one of the typical ways to promote mixing performance by the spatial chaotic mixing, has been investigated experimentally and numerically. The mixing time was measured by the decolorization method and it was found that the inclined impeller could reduce mixing time compared to that obtained by the vertically located impeller in laminar flow region. The effect of eccentric position of inclined impeller on mixing time was also studied and a significant reduction of mixing time was observed. To confirm the experimental results, the velocity profiles were calculated numerically and two novel numerical simulation methods were proposed.


2012 ◽  
Vol 550-553 ◽  
pp. 2964-2967
Author(s):  
De Yu Luan ◽  
Shen Jie Zhou ◽  
Song Ying Chen

Abstract: The 3D flow field generated by a dual-impeller in the agitation of glycerin fluid was simulated using the commercial CFD package. The flow was modeled as laminar and a multiple reference frame (MRF) approach was used to solve the discretized equations of motion. The velocity profiles with a dual-impeller rotating at constant speed of 200r/min and at different layer clearances were obtained. By analysis to their axial and radial velocity vector plots and velocity distribution curves, it is found that the velocity distributions of the dual 6-bladed radial disc turbines (2-6DT) are better when the clearance is bigger or equal to the T/2, accompanied with the flow field pattern of parallel flow. Moreover,when the clearance is smaller or equal to the T/3, there are more advantages for 6-bladed radial disc turbines + pitch 4-bladed turbines (6DT+PTB) than other combinations,followed by the flow field pattern of connected flow.


2015 ◽  
Vol 779 ◽  
pp. 125-132
Author(s):  
Ying Na Liang

Computational fluid dynamics (CFD) method was applied to study the flow field in cylindrical stirred tank mixing non-Newtonian fluid with double layer combined impeller of upper-straight-blade and lower-inclined-blade. The laminar model and the multiple reference frame (MRF) were employed to simulate the three-dimensional flow field in stirred tank with double layer combined impeller rotating at a constant speed of 200 r/min mixing the mixture of glycerin and water centrally、eccentrically and relative eccentrically, and three different flow structures in stirred tank were obtained. Analyzing the velocity vectors, the velocity contours and the axial、radial and tangent velocity distribution curves, the rule of velocity field with the blade combined form and the stirring structure was discussed. The research provided the valuable reference for the design and practical application of the laminar stirred tank.


2009 ◽  
Vol 64 (12) ◽  
pp. 2926-2933 ◽  
Author(s):  
Qinghua Zhang ◽  
Yumei Yong ◽  
Zai-Sha Mao ◽  
Chao Yang ◽  
Chengjun Zhao

2013 ◽  
Vol 732-733 ◽  
pp. 432-435 ◽  
Author(s):  
Zong Rui Hao ◽  
Juan Xu ◽  
Hai Yan Bie ◽  
Zhong Hai Zhou

Flow characteristics of stirred tanks with different structures were calculated by taking RNG k-ε model as the turbulent flow model. The results showed that at the same rotational speed, a large number of axial and radial vortexes were formed in the stirred tank with the baffle. The velocity in the blade area was high, and it decreased rapidly with the increasing distance to the blade. The double peak area of the radial velocity was formed in the stirred tank with baffle, and the high and low speed cycles were obtained in the cross-section. The baffle increased not only the axial circulation of the liquid in the tank but also the radial circulation, which help to mix the liquid.


2013 ◽  
Vol 675 ◽  
pp. 129-134
Author(s):  
Meng Zhou

The Fluid Flow of Liquid Metal in Ladles of CAS-OB Refining Process Is a Complicated Turbulent Transmission Process. it Behaves much More Complicated than in Traditional Ladle because of Immersion Snorkel. this Paper Describes Properties of Liquid Metal Based on Full Buoyancy Model. the Author Analyzes the Characteristics of Flow Field in Single and Double-nozzles Bottom Blowing Condition through Numerical Simulation Method. Double-nozzles Bottom Blowing Could Improve Blending Effect in the Region where Is Weak Mixing. this Paper Also Draws an Empirical Formula which Tells how Gas Blowing and Immersion Depth Influence Mixing Time in CAS-OB Ladle through Dimensionless Analysis.


2021 ◽  
Vol 39 (1) ◽  
pp. 251-261
Author(s):  
Abderrahim Mokhefi ◽  
Mohamed Bouanini ◽  
Mohammed Elmir

The purpose of research presented in this paper is to study the thermal and hydrodynamic effect of the non-isothermal laminar flow of a Al2O3-water nanofluid having shear thinning behavior in a mechanically stirred tank using the finite element method. Numerical simulation has been performed for a non-stationary two-dimensional flow controlled by certain influencing parameters such as the Reynolds number (1 ≤ Re ≤ 200), the behavior index (0.6 ≤ n ≤ 1) and the volume fraction of the alumina nanoparticles (0 ≤ φ ≤ 0.1). The simulation results obtained show that the addition of the Al2O3 nanoparticles in the base fluid leads to a significant enhancement in the heat transfer in the stirred tank compared to the base fluid. On the other hand, we note a slight decrease in the heat transfer with the decrease in the behavior index. It has also been noted, that the agitation power increases relatively with the volume fraction of the Alumina nanoparticles.


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