Continuous flow mixing of two miscible liquids of different densities

1970 ◽  
Vol 48 (5) ◽  
pp. 484-490 ◽  
Author(s):  
Martin Pelletier ◽  
Leonce Cloutier
Keyword(s):  
Continuous Flow ◽  
Flow Mixing ◽  
Miscible Liquids

scholarly journals Mixing characterization in different helically coiled configurations by laser-induced fluorescence

2020 ◽  
Vol 61 (9) ◽  
Author(s):  
P. Kováts ◽  
C. Velten ◽  
M. Mansour ◽  
D. Thévenin ◽  
K. Zähringer
Keyword(s):  
Cross Sections ◽  
Quantitative Measure ◽  
Laser Induced Fluorescence ◽  
Helical Coil ◽  
Mixing Coefficient ◽  
Dean Vortices ◽  
Flow Mixing ◽  
Mixing Coefficients ◽  
Mass Fractions ◽  
Miscible Liquids

AbstractFlow Mixing of two miscible liquids has been characterized experimentally in three different helically coiled reactor configurations of two different lengths in the laminar flow regime at Re = 50…1000. A straight helical coil, a coiled flow inverter, and a new coiled flow reverser have been built, each in a 3-turn and a 6-turn configuration. Laser-induced fluorescence of resorufin has been used to visualize and quantify mixing in cross-sections throughout the reactors. A mixing coefficient is derived from the fluorescence images to allow for a quantitative measure and comparison of the six configurations. It becomes obvious from these experimental results, that an early flow redirection in the helical configuration is beneficial to mixing. The 3-turn reactors achieve nearly the same mixing coefficients as the 6-turn reactors with the double length. This can be explained by the stabilizing effect of the Dean vortices in the helix, which develop during the first two turns. After that, the liquid is trapped inside the vortices and further mixing is inhibited. Accordingly, the coiled flow inverter and coiled flow reverser configurations lead to much higher mixing coefficients than the straight helical coil. The results of these measurements are now used for validation of numerical simulations, which reproduce the geometrical and flow conditions of the experiments. Some exemplary results of these calculations are also shown in this article. Graphic abstract Mass fractions of tracer fluid at Re = 500 in the six examined helix configurations.

Tomography images to analyze the deformation of the cavern in the continuous-flow mixing of non-Newtonian fluids

AIChE Journal ◽  
2013 ◽  
Vol 60 (1) ◽  
pp. 315-331 ◽  
Author(s):  
Dineshkumar Patel ◽  
Farhad Ein-Mozaffari ◽  
Mehrab Mehrvar
Keyword(s):  
Continuous Flow ◽  
Newtonian Fluids ◽  
Flow Mixing

Mass transfer in a continuous-flow mixing vessel

AIChE Journal ◽  
1957 ◽  
Vol 3 (2) ◽  
pp. 283-286 ◽  
Author(s):  
D. W. Humphrey ◽  
H. C. Van Ness
Keyword(s):  
Mass Transfer ◽  
Continuous Flow ◽  
Flow Mixing

scholarly journals Using tomography, CFD, and dynamic tests to study the continuous-flow mixing of yield-pseudoplastic fluids

2021 ◽  
Author(s):  
Dineshkumar Patel
Keyword(s):  
Yield Stress ◽  
Continuous Flow ◽  
Mixing Time ◽  
Mixed Volume ◽  
Dynamic Tests ◽  
Ideal Mixing ◽  
Flow Mixing ◽  
Batch Mixing ◽  
Pseudoplastic Fluids ◽  
2D And 3D

The major technological challenges faced by modern chemical industries are non-ideal flows such as dead zones and channeling encountered in the mixing of fluids with complex rheology. These cause sub-optimal mixing and lead to low quality products and high costs of raw materials. Therefore, the core objectives of this study were to develop methodology and tools to design an efficient continuous-flow mixing system for the fluids with complex rheology using electrical resistance tomography (ERT), computational fluid dynamics (CFD), and dynamic tests. The xanthan gum solution, which is a pesudoplastic fluid with yield stress, was used to study the dynamic behavior of the continuous-flow mixing process. The power consumption, cavern size, mixing time, and the extents of channelling and the fraction of fully mixed volume were successfully determined using dynamic tests, ERT tests, and CFD simulations and used as mixing quality criteria. A novel and efficient method was developed for flow visualization in the continuous-flow mixing of opaque fluids using 2D and 3D tomograms. A unique study on identifying the sources of flow non-ideality in non-Newtonian fluids with yield stress was done by visualizing the flow pattern inside the continuous-flow mixing vessel using 2D and 3D tomograms. The deformation of the cavern was analyzed and quantified in the continuous-flow mixing system for yield-pseudoplastic fluids using ERT. Moreover, the cavern volume was compared with the fully mixed volume and it was found that the latter was higher due to the extra momentum induced by the inlet-outlet flow. A novel study on exploring the effect of the rheological parameters of the pseudoplastic fluids with yield stress on the non ideal flows in a continuous-flow mixing system was performed using CFD. The CFD results revealed that the mixing quality was improved when the degree of the shear thinning was increased. The ratio of the residence time to the batch mixing time was evaluated to achieve ideal mixing for the continuous-flow mixing of yield-pseudoplastic fluids using dynamic tests and ERT. It was found that the ratio of residence time to the batch mixing time should be at least 8.2 or higher to achieve ideal mixing.

Apparatus for continuous flow mixing of explosive gases

1968 ◽  
Vol 1 (4) ◽  
pp. 459-462 ◽  
Author(s):  
M M Kamel ◽  
E Lundstrom ◽  
A K Oppenheim
Keyword(s):  
Continuous Flow ◽  
Flow Mixing
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