scholarly journals Experimental studies on hydrodynamic aspects for mixing of non-Newtonian fluids in a Komax static mixer

2020 ◽  
pp. 9-9
Author(s):  
D. Revathi ◽  
K. Saravanan
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Unit Length ◽  
Continuous Process ◽  
Experimental Studies ◽  
Vital Role ◽  
Newtonian Fluids ◽  
Static Mixer ◽  
Static Mixers ◽  
Mixing Performance

Mixing is the degree of homogeneity of two or more phases and it plays a vital role in the quality of the final product. It is conventionally carried out by mechanical agitators or by static mixers. Static mixers are a series of geometric mixing elements fixed within a pipe, which use the energy of the flow stream to create mixing between two or more fluids or to inject metered liquid into a continuous process. The objective of this work is to predict hydrodynamic aspects of the static mixer designed. The mixing performance of Komax static mixer has been determined for the blending of non-Newtonian fluid streams with identical or different rheology by using experimental study. The energy needed for mixing comes from the force created by the liquid due to turbulence and the geometry of the static mixer. Pressure drop in static mixer depend strongly on geometric arrangement of the inserts, properties of fluids to be mixed and flow conditions. Hence pressure drop studies are carried out for different flow rates of fluids with different concentrations of two non-Newtonian fluids. Starch and xanthan gum solutions are used as working fluids. It is observed from the experimental results that the pressure drop per unit length increases as the fluid flow rate increases and the nature of fluid flow varies with the velocity of the fluids.

Numerical Simulation and Mixing Study of Non-Newtonian Fluids in an Industrial Helical Static Mixer

2004 ◽  
Author(s):  
Ramin K. Rahmani ◽  
Theo G. Keith ◽  
Anahita Ayasoufi
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Single Phase ◽  
Engineering Application ◽  
Newtonian Fluids ◽  
Phase Reaction ◽  
Static Mixer ◽  
Fluid Type ◽  
Mixing Processes ◽  
Static Mixers

Static mixers are increasingly being used to perform a variety of mixing tasks in industries, ranging from simple blending to complex multi-phase reaction systems. Use of static mixers to process non-Newtonian fluids is quite common. Data on the pressure drop of non-Newtonian fluids in static mixers and the degree of mixing of materials through the mixer are very useful in the design and engineering application of these tools. This paper extends a previous study by the authors on an industrial helical static mixer and illustrates how static mixing processes of single-phase viscous liquids can be simulated numerically. A further aim is to provide an improved understanding of the flow pattern of non-Newtonian single-phase liquids through the mixer. A three-dimensional finite volume simulation is used to study the performance of the mixer. The non-Newtonian fluid is modeled by the Carreau law model for the shear stress. The effects of the Reynolds number of the flow and also properties of non-Newtonian fluids on the static mixer performance have been studied. The flow velocities, pressure drops, etc. are calculated for various flow rates. The computed pressure drop is in good agreement with existing experimental data. A comparison of the mixer performance for both Newtonian and non-Newtonian fluids is presented. It is shown that for low Reynolds number flows, the fluid type is less effective on the degree of mixing, while as flow Reynolds number increases and the viscosity decreases, it manifests more influence on the downstream mixing. It is also shown that the fluid type has a major impact on the pressure drop across the mixer.

Numerical Simulation and Mixing Study of Pseudoplastic Fluids in an Industrial Helical Static Mixer

2005 ◽  
Vol 128 (3) ◽  
pp. 467-480 ◽  
Author(s):  
Ramin K. Rahmani ◽  
Theo G. Keith ◽  
Anahita Ayasoufi
Keyword(s):  
Pressure Drop ◽  
Three Dimensional ◽  
Engineering Application ◽  
Newtonian Fluids ◽  
Static Mixer ◽  
Fluid Type ◽  
Mixing Processes ◽  
Static Mixers ◽  
Numerical Predictions ◽  
Pseudoplastic Fluids

Static mixers are increasingly being used to perform a variety of mixing tasks in industries, ranging from simple blending to complex multiphase reaction systems. Use of static mixers to process non-Newtonian fluids is quite common. Data on the pressure drop of non-Newtonian fluids in static mixers and the degree of mixing of materials through the mixer are very useful in the design and engineering application of these tools. This paper extends a previous study by the authors on an industrial helical static mixer and illustrates how static mixing processes of single-phase viscous liquids can be simulated numerically. A further aim is to provide an improved understanding of the flow pattern of pseudoplastic liquids through the mixer. A three-dimensional finite volume simulation is used to study the performance of the mixer. The flow velocities, pressure drops, etc., are calculated for various flow rates, using the Carreau and the power law models for non-Newtonian fluids. The numerical predictions by these two models are compared to existing experimental data. Also, a comparison of the mixer performance for both Newtonian and pseudoplastic fluids is presented. The effects of the Reynolds number of the flow and also properties of pseudoplastic fluids on the static mixer performance have been studied. It is shown that for the materials studied here, the fluid type is not effective on the degree of mixing. It is also shown that the fluid type has a major impact on the pressure drop across the mixer.

scholarly journals Effect of Aspect Ratio on the Mixing Performance in the Kenics Static Mixer

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 464
Author(s):  
Xingren Jiang ◽  
Ning Yang ◽  
Rijie Wang
Keyword(s):  
Pharmaceutical Industry ◽  
Aspect Ratio ◽  
Flow Reactor ◽  
Mixing Time ◽  
Continuous Process ◽  
Scale Up ◽  
Influence Factors ◽  
Continuous Manufacturing ◽  
Static Mixer ◽  
Mixing Performance

Continuous manufacturing has received increasing interest because of the advantages of intrinsic safety and enhanced mass transfer in the pharmaceutical industry. However, the difficulty for scale-up has limited the application of continuous manufacturing for a long time. Recently, the tubular flow reactor equipped with the Kenics static mixer appears to be a solution for the continuous process scale-up. Although many influence factors on the mixing performance in the Kenics static mixer have been investigated, little research has been carried out on the aspect ratio. In this study, we used the coefficient of variation as the mixing evaluation index to investigate the effect of the aspect ratio (0.2–2) on the Kenics static mixer’s mixing performance. The results indicate that a low aspect ratio helps obtain a shorter mixing time and mixer length. This study suggests that adjusting the aspect ratio of the Kenics static mixer can be a new strategy for the scale-up of a continuous process in the pharmaceutical industry.

Simulation of the Laminar Flow in a PRIMIX Static Mixer

2002 ◽  
Author(s):  
R. F. Mudde ◽  
C. Van Pijpen ◽  
R. Beugels
Keyword(s):  
Pressure Drop ◽  
Particle Tracking ◽  
Experimental Validation ◽  
Independent Solution ◽  
High Accuracy ◽  
Static Mixer ◽  
Laminar Regime ◽  
Time Step ◽  
Static Mixers ◽  
Direct Use

The PRIMIX helical static mixer has been investigated using numerical simulations. The flow is in the laminar regime (Re = 1 to 1000). The simulations concentrate on the pressure drop and on the use of particle tracking for mixing studies. For the pressure drop, experimental validation is provided. It is found that the pressure drop can be simulated with high accuracy for Re < 350. For higher Re-values no grid independent solution could be obtained and the experimental results no longer agree with those of the simulations. The simulated pressure drop results scaled to the empty pipe pressure drop, can be well summarized as K = 4.99 + Re/31.4. Using Particle Tracking it has been possible to reproduce literature data. However, it has been shown that the obtained results are rather sensitive to the choice of the time step. This limits the direct use of particle tracking techniques for studying the mixing of static mixers in the laminar regime.

Analysis of the Pressure Drop of the Horizontal Liquid-Solid Circulation Fluidization Bed with Kenics Static Mixers

2013 ◽  
Vol 291-294 ◽  
pp. 791-794
Author(s):  
Yan Liu ◽  
Shao Feng Zhang ◽  
Jiang Tao Wang
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Aspect Ratio ◽  
Friction Factor ◽  
Static Mixer ◽  
Experiment Data ◽  
Dimensionless Parameters ◽  
Static Mixers ◽  
Dimensionless Pressure ◽  
Dimension Analysis

In order to obtain the pressure drop of the horizontal liquid-solid circulation fluidization bed with Kenics static mixers, experiments were carried out in four Kenics static mixers with different aspect ratio of mixing element(AR) over a range of 30000 to 51000 to get pressure drop data. Dimension analysis revealed that the pressure drop characteristic of the Kenics static mixer can be described by three dimensionless parameters, such as the friction factor, Reynolds number, and aspect ratio of mixing element. According to the experiment data, a new dimensionless pressure drop correlation was developed. The results indicate that the value of Cf becomes constant and has no correlation with the value of Re in fixed AR. The value of Cf was increased with the increase of AR.

A Comparison Between Lattice-Boltzmann and Finite-Element Simulations of Fluid Flow in Static Mixer Reactors

1998 ◽  
Vol 09 (08) ◽  
pp. 1123-1128 ◽  
Author(s):  
D. Kandhai ◽  
D. J.-E. Vidal ◽  
A. G. Hoekstra ◽  
H. Hoefsloot ◽  
P. Iedema ◽  
...  
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Fluid Flow ◽  
Lattice Boltzmann ◽  
Complex Geometry ◽  
Simulation Methods ◽  
Static Mixer ◽  
Chemical Reactors ◽  
Mixing Performance ◽  
Boltzmann Method

We present a comparison between the finite-element and the lattice-Boltzmann method for simulating fluid flow in a SMRX static mixer reactor. The SMRX static mixer is a piece of equipment with excellent mixing performance and it is used in highly efficient chemical reactors for viscous systems like polymers. The complex geometry of this mixer makes such 3D simulations nontrivial. An excellent agreement between the results of the two simulation methods and experimental data was found.

Enhancement of the performance of a static mixer by combining the converging/diverging tube shapes and the baffling techniques

2020 ◽  
Vol 18 (4) ◽  
Author(s):  
Noureddine Kaid ◽  
Houari Ameur
Keyword(s):  
Pressure Drop ◽  
Cost Effective ◽  
Reynolds Numbers ◽  
Static Mixer ◽  
Mixing Index ◽  
Maximum Enhancement ◽  
Low Reynolds Numbers ◽  
Static Mixers ◽  
Pressure Losses ◽  
Inclination Angles

AbstractThe performance of a newly designed static mixer is explored in this paper by numerical simulations. It concerns a converging/diverging circular tube equipped with opposing and staggered baffles. This new design of static mixer presents a cost-effective, easy-to-design, easy-to-maintain choice, with a minimum pressure drop and a good mixing index at low Reynolds numbers (from 60 to 700), to the currently used static mixers. The investigation was carried out numerically for different baffle clearances (cl/D = 0.3, 0.5, 0.7 and 1.0, respectively) and inclination angles (α = 0°, 30° and 45°, respectively), different ratios of inlet diameter-to-outlet diameter (Dd = d/D = 0.6, 0.8, 1.0, 1.2 and 1.4, respectively) and different Reynolds number values. The obtained results revealed that the diverging tube favors the mixing index while reducing the pressure drop. For a dimensionless baffle clearance (cl/D) of 0.5 and Re = 700, the mixing index has been increased from 0.78 for a simple tube (d/D = 1) having vertical baffles (α = 0°) until 0.95 for a diverging tube at the ratio (d/D) of 1.4 with the same vertical baffles (α = 0°). The increase in the ratio d/D has also yielded a decrease in pressure losses. Compared to the simple static mixer without baffles and having the same inlet as outlet sections, the maximum enhancement in mixing index was about 315.84% when d/D = 1.4 and Cl/D = 0.3 and α = 0°. However, a reduction in pressure drop by about 92% may be obtained when α = 30° with only a reduction in mixing index by 14% (compared to α = 0°).

Newtonian and Non-Newtonian Fluids: Velocity Profiles, Viscosity Data, and Laminar Flow Friction Factor Equations for Flow in a Circular Duct

2008 ◽  
Author(s):  
Melissa M. Simpson ◽  
William S. Janna
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Laminar Flow ◽  
Friction Factor ◽  
Newtonian Fluid ◽  
Velocity Profiles ◽  
Newtonian Fluids ◽  
Viscosity Data ◽  
Circular Duct ◽  
Flow Friction

Newtonian fluid flow in a duct has been studied extensively, and velocity profiles for both laminar and turbulent flows can be found in countless references. Non-Newtonian fluids have also been studied extensively, however, but are not given the same attention in the Mechanical Engineering curriculum. Because of a perceived need for the study of such fluids, data were collected and analyzed for various common non-Newtonian fluids in order to make the topic more compelling for study. The viscosity and apparent viscosity of non-Newtonian fluids are both defined in this paper. A comparison is made between these fluids and Newtonian fluids. Velocity profiles for Newtonian and non-Newtonian fluid flow in a circular duct are described and sketched. Included are profiles for dilatant, pseudoplastic and Bingham fluids. Only laminar flow is considered, because the differences for turbulent flow are less distinct. Also included is a procedure for determining the laminar flow friction factor which allows for calculating pressure drop. The laminar flow friction factor in classical non-Newtonian fluid studies is the Fanning friction factor. The equations developed in this study involve the Darcy-Weisbach friction factor which is preferred for Newtonian fluids. Also presented in this paper are viscosity data of Heinz Ketchup, Kroger Honey, Jif Creamy Peanut Butter, and Kraft Mayonnaise. These data were obtained with a TA viscometer. The results of this study will thus provide the student with the following for non-Newtonian fluids: • Viscosity data and how it is measured for several common non-Newtonian fluids; • A knowledge of velocity profiles for laminar flow in a circular duct for both Newtonian and non-Newtonian fluids; • A procedure for determining friction factor and calculating pressure drop for non-Newtonian flow in a duct.

Simulation of Laminar Mixing in Fractal Perforated Plate Static Mixers

2013 ◽  
Vol 845 ◽  
pp. 31-35 ◽  
Author(s):  
Bukhari Manshoor ◽  
Izzuddin Zaman ◽  
Mohd Zamani Ngali ◽  
Amir Khalid
Keyword(s):  
Pressure Drop ◽  
Perforated Plate ◽  
Reynolds Numbers ◽  
Static Mixer ◽  
Static Mixers ◽  
Flow Mixing ◽  
Laminar Mixing ◽  
Initial Stage ◽  
Ongoing Work ◽  
New Type

This paper examines the performance of a new type of static mixer known as Fractal Plate Static Mixers. A simulation study was performed to investigate the pressure drop across different numbers of mixing elements (1, 2 and 3). The effectiveness of mixing was assessed by analyzing the coefficient of variation (CoV) of the flow within the range of 0 to 1. The value of CoV that approaching 1 is categorized as a total segregation, while close to 0 indicates a good mixing. The Reynolds number of the study was chosen between 500 and 2000 based on the unobstructed pipe diameter. Results showed that the mixing elements in the flow stream promote a non-laminar, turbulent-like flow which substantially enhances the mixing. By adding more mixing element, it was found that the flow mixing was enhanced in particular at lower Reynolds numbers. In spite of this advantage, the pressure drop was found increased in proportional to the number of mixing elements. This work presents an initial stage of ongoing work to develop a new type of static mixers that based on perforated plate.

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