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.

Quantitative Mixing Analysis of Laminar Flow in Circle Grid Perforated Plate with 50% Porosity Static Mixer

2014 ◽  
Vol 541-542 ◽  
pp. 836-840 ◽  
Author(s):  
Mat Loddin Mohd Zamadi ◽  
Amir Khalid ◽  
Bukhari Manshoor
Keyword(s):  
Laminar Flow ◽  
Fluid Dynamic ◽  
Perforated Plate ◽  
Reynolds Numbers ◽  
Manufacturing Cost ◽  
Static Mixer ◽  
New Approach ◽  
Static Mixers ◽  
Ansys Cfx ◽  
Research Findings

The applications of the static mixers are widely applied in many industries to obtain the desired type of mixing. In this context, to perform the mixing process should have two different fluids that also have different properties which will combines it in a single equipment to make an another fluid. The main objective of this research study is to propose a new approach of fractal concept (circle grid perforated plate) for internal rapid mixing by determining the coefficient of variation (COV). This study was implemented by fully numerical simulations. The simulations of mixing fluid were carried out with the help of commercial computational fluid dynamic (CFD) package ANSYS CFX 14.0 software. The simulation was done primarily in cylindrical pipe with insertions of circle grid perforated plate with porosity of 50%. Three levels of laminar flow have been chosen to result in Reynolds numbers (Re) equal to 100, 200 and 400. The effectiveness of circle grid perforated plate static mixer has been evaluated by comparing the homogeneity level of mixing fluids to the Kenics static mixer that readily available in industries applications. Based on the research findings, the COV value for circle grid perforated plate with 50% porosity at Re 100 was 0.0744 which is out of the range while Reynolds number at 200 and 400 were 0.0483 and 0.0247 respectively which are in the range in term of reasonable target of mixing homogeneity. The values of COV between 0.01 and 0.05 are the reasonable target for many applications. In term of manufacturing cost and energy loss due to static mixer, definitely this new approach of 50% porosity circle grid perforated plate is better design compared to the Kenics static mixer because of lower number of inserts and simpler design of static mixer to produce.

Effect of Porosity on Circle Grid Perforated Plate Performance as a Static Mixer in Laminar Flow

2015 ◽  
Vol 786 ◽  
pp. 188-192
Author(s):  
Bukhari Manshoor ◽  
M.Z. Mat Loddin ◽  
Amir Khalid ◽  
Izzuddin Zaman
Keyword(s):  
Laminar Flow ◽  
Perforated Plate ◽  
Reynolds Numbers ◽  
Static Mixer ◽  
New Approach ◽  
Static Mixers ◽  
Ansys Cfx ◽  
Industry Applications ◽  
Simulation Results ◽  
The Many

Mixing is one of the important processes to the many industries. Fluid mixing process typically involves three phases of fluid in the form of liquids, gases and solids. To obtain a desired type of mixing, one of the devices that can be use is a static mixer. In this study, a perforated plate static mixer with circle grid fractal design with two grades of porosity which are 50% and 75% will introduce. The purpose of implementing the two grades porosity of perforated plate in this study is to determine a performance of the two static mixers. In order to achieve the objective, the simulations of mixing fluid were carried out by using ANSYS CFX software. The simulation was carrying out primarily in cylindrical pipe with insertions of circle grid perforated plate. Three levels of laminar flow had been used which is Reynolds numbers (Re) equal to 100, 200 and 400. The performance of circle grid perforated plate static mixer will be evaluated by determining the Coefficient of Variation (COV). The simulation results also were compared in term of homogeneity level of mixing fluids to the Kenics static mixer. Based on the simulation results, the value of COV at selected plane in pipeline simulated for Kenics static mixer and the two grades porosity of perforated plate at Re = 400 are 0.000703, 0.0247and 0.00427 respectively. Since the values of COV between 0.01 and 0.05 are a reasonable target for many industry applications, the results for new approach of static mixer represent completely homogeneous mixing fluid for this application. Definitely this new approach of circle grid perforated plate with fractal design gave better results because of lower number of inserts and simple design of static mixer.

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°).

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.

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.

Large-Eddy Turbulent Flow Simulation of a KOMAX Static Mixer

2008 ◽  
Author(s):  
Ramin K. Rahmani ◽  
Theo G. Keith ◽  
Anahita Ayasoufi
Keyword(s):  
Turbulent Flow ◽  
Critical Role ◽  
Flow Simulation ◽  
Reynolds Numbers ◽  
Static Mixer ◽  
Viscous Liquids ◽  
Pressure Drops ◽  
Static Mixers ◽  
Eddy Simulation ◽  
Large Eddy

Viscous liquids have to be homogenized in continuous operations in many branches of processing industries; and therefore, fluid mixing plays a critical role in the success or failure of many industrial processes. Consequences of improper mixing include non-reproducible processing conditions and lowered product quality, resulting in the need for more elaborate downstream processes and increased costs. The range of practical flow Reynolds numbers for KOMAX static mixers in industry is usually from moderate values (Re ≈ 0) to very large values (e.g. Re ≈ 5,000,000). However, most of industrial applicants have a very small flow to moderate Reynolds numbers (e.g. Re ≈ 5,000). This paper presents an improved understanding of the turbulent flow pattern for single-phase liquids through the mixer. Large-Eddy Simulation (LES) model is applied to the flow in a KOMAX static mixer to calculate the flow velocities, pressure drops, etc. Using a variety of predictive tools, the mixing results are obtained.

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.

Mixing Analysis of Laminar Flow in Static Mixers with Circle Grid Fractal Perforated Plate Elements

2014 ◽  
Vol 607 ◽  
pp. 417-421
Author(s):  
Bukhari Manshoor ◽  
Izzuddin Zaman ◽  
Azwan Sapit ◽  
Amir Khalid
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Laminar Flow ◽  
Flow Pattern ◽  
Coefficient Of Variation ◽  
Fluid Dynamic ◽  
Perforated Plate ◽  
Static Mixers ◽  
Plate Elements ◽  
Flow Splitting

The static mixers are widely used in many industries to obtain the desired type of mixing. In the context of mixing process, two different fluids and have a different properties will mix in a single equipment to produce an another fluid with a new property. In this research, a new approach of static mixers was proposed for pipeline mixing. The flow pattern, pressure drop and mixing characteristics (coefficient of variation) were carried out by means of computer simulations. The static mixers introduced here consists of a series of perforated plate with circle grids fractal pattern elements. The simulations work were carried out by using a commercial package of Computational Fluid Dynamic (CFD), ANSYS CFX 14.0 software. Three levels of laminar flow with Reynolds numbers (Re) of 100, 200 and 400 respectively had been used to investigate the performance of the static mixers introduced here. The effectiveness of circle grid perforated plate static mixer had been evaluated by comparing the homogeneity level of mixing fluids for each flow simulated. The simulations gave a new insights in the flow pattern in circle grids fractal perforated plate elements. The pressure drop predictions compare favorably with literature data and the coefficient of variation (COV) value for circle grid perforated plate with 50% porosity at Reynolds number 100 was 0.0744 which is out of the range meanwhile at Reynolds number 200 and 400 was 0.0483 and 0.0247 respectively which are in the range of reasonable target for many applications. Mixing in the elements occurs through a combination of flow splitting and shearing at the junctions of successive elements. Besides that, simple installation and manufacturing of this type of static mixers makes the fractal perforated plate’s element an excellent static mixing device.

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.

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